Finding the right home base, buying the ideal travel pass, etc.

You might try booking.com to check what’s available for your dates. I see there’s a Radisson but no Marriott in Bern. I don’t remember seeing any American type hotels in Wengen.

Checking I see there are Best Westerns in both Bern and Wengen. Maybe someone can give you more info on the particular hotels. I remember staying in a Best Western in France and it was not typical of what you would find in a BW in US.

Thank you Margie.
I will give it another look.

As Margie said, use Booking.com to search for lodging for the dates you need and with your requirements: one room, 4 people, etc. I personally have not been in any hotel room in Europe with 2 full-sized beds, so perhaps, search for “family rooms.”
However, book directly with the hotel. There is a Best Western in Bern near the train station that is listed in the RS Switzerland book. My husband and I have reservations for that hotel in June.

Check into the Novotel and Ibis hotels, both of which are budget European chains. Ibis and Novotel both have hotels at the Bern Expo, which is just 4 miles and a 15 to 20-minute tram ride to Bern’s Old Town, or “Innere Stadt.” That is where you’ll find Bern’s central train station as well.

Thank you all so much for the additional responses.
Novotel and Ibis are my top choices so far and will research the Best Western. If Rick recommends it, then it is worth a shot. 😃

Any advice on Air BnB?

In general, American-style chain hotels like Marriott/Hilton/etc are less common outside the major business cities in Switzerland.
Rooms are usually smaller here and it can be difficult to find a city hotel room that takes 4 people - especially since your kids are older teens and not little kids, many places consider them adults for booking purposes and rooms often max out at 3 people. Novotel is ok, part of the French Accor group, more of a mid-range business hotel. The one in Bern is near the convention center (not an especially exciting area but not difficult to get to central Bern, about 8 mins by tram, free transport with hotel booking). You could look at something like Da Maurizio Suites or the related Max Aviation apartments - they are in a nice neighborhood full of embassies a little outside the historic center. Also takes about 7 minutes to get into central Bern via tram.
Family rooms are more common in the mountains, but if you would rather book an apartment, hopefully someone can suggest places available outside of the airbnb platform.

Why would you be reluctant to book an Airbnb? For a family where you need multiple rooms/beds, a chalet apartment can be a great option. You also get a kitchen where you can store snacks, easy breakfasts and lunches for on the go. You don't have to just look at airbnb, also check Interhome, e-domizil, chalet.myswitzerland.com, as well as google "location x apartment rental" In Wengen you can also look at Wengen Apartments, Alpine Holiday Services, etc. These are local Wengen rental companies.

I don't know your full itinerary, but if you want to see the Berner Oberland, I'd recommend staying IN the mountains instead of in Bern where you have to transport back and forth every day. It will be a much different experience being in the mountains or at least in Interlaken where you're much closer for your lake days and mountain activities.

Well, I'm reluctant to book AirBnB because it is so harmful to local housing conditions, and is often heavily regulated, leading to sudden detection of unregistered or illegal rentals, after booking. My ritzy New Jersey suburb banned rentals under 30 days years ago. If I don't want rowdy reunions next to me, how can I impose them others?

Vacation rentals in Switzerland in the mountains are extremely regulated, so renting one via any of the local rental companies I mentioned isn’t an issue and helps their local tourist economy in the same way staying in a hotel does. Most of the rentals you find on Airbnb in these areas are also available through the local companies, they just cross post.

Thank you so much for taking the time to offer suggestions. After further research, I canceled the hotel reservation in Bern and I am looking for a home base close to Interlaken, but not too touristy.

My search has expanded to Airbnb since most of the hotels I researched are not a good fit for us. I was disappointed to learn that not all rentals participate in the association that offers public transport discounts.

We prefer a quieter area with restaurants and grocery stores within walking distance, such as Spiez or the town nearby, Einigen. See below from swissglorious.com

Einigen has a long and fascinating history that dates back to the Roman Empire. The town was an important stop on the trade route between Italy and Germany and its strategic location led to frequent battles and invasions. Over the centuries, Einigen has been ruled by various feudal lords and wealthy merchant families, each leaving their mark on the town's architecture and culture. Today, visitors can explore the old town and see the many historic buildings and monuments that still stand, including the ruins of a medieval castle.

How can I tell if an area is covered in the Berner Oberland pass?

Still tweaking our itinerary. We will definitely be going to Zermatt to view the spectacular Matterhorn.
Would welcome additional information on the Swiss apartment rental companies?

Thanks so much.

How can I tell if an area is covered in the Berner Oberland pass?

from the Pass website, on the main page, drill down under " Where is the ticket passport valid?"

https://www.berneseoberlandpass.ch/maps-bernese-oberland/

also https://www.berneseoberlandpass.ch/public-transport/

I had better luck with VRBO (versus Airbnb and local websites), but also some hotels have apartments (one of the chains in Murren does this)—possibly something to pursue.

Reference what I said above….
“ You don't have to just look at airbnb, also check Interhome, e-domizil, chalet.myswitzerland.com, as well as google "location x apartment rental" In Wengen you can also look at Wengen Apartments, Alpine Holiday Services, etc. These are local Wengen rental companies.”

The problem with staying somewhere like Einigen is that it requires a bus connection to Spiez every time you want to go somewhere. Likewise, in Spiez because it’s a very hilly town it’s a 15 minute uphill/downhill walk from the train station to the waterfront.

A base really depends on your list of activities. If you want to concentrate on mountain activities, then stay IN the mountains somewhere with good connectivity like Wengen. If you’re wanting somewhere more central for transportation for longer day trips, then you’re better off in a major transportation hub like Interlaken or Thun in lodging that doesn’t require a bus connection. If you want to just be off the beaten path to chill and don’t care as much about day trips, then certainly somewhere like Einigen could be great, as you won’t get many tourists.

If you’re wanting to see the Matterhorn, then you’ll need to stay in Zermatt for some time.

To really help you, it’s helpful to know your length of trip in nights, entry/exit points and what you want to see.

Great tips and suggestions. Thanks for the information @wanderweg, nigel, and others.