Global rail pass.

It is sufficient, but probably excessive.
You say you have two rail journeys:
1) Somewhere in Germany (where?) to Innsbruck
2) Innsbruck to Zürich (is that Zürich city, or Zürich airport?)

It is almost certainly a lot cheaper to buy two advance purchase tickets direct from the rail company.
For example ÖBB (Austrian Federal Railways https://www.oebb.at/en/ ) are currently selling tickets Innsbruck to Zürich HB, for a random date in January, for €19 per person.
How much per day will a pass cost you?

I saw at db rail site it would cost $158. Usd for myself and husband to travel from innsbruck to zurich. We are also traveling around southern Bavaria for a few days, Junich to Salzburg and other journeys.

Travelling around Bavaria (I think you meant Munich?) can be done for an entire day for two people for 32€. Not each, for the two, the entire state of Bavaria anywhere and to Salzburg, as much as you can eat in a day, after 9:00 weekdays, no restriction weekends and holiday, 2nd class on regional trains. If you have specific journeys there are often even cheaper trains. You can't travel for 32€ a day for 2 (that 16.00€ each, including local city transportation and buses too) using rail passes, especially the Global.

You may need what you contemplate but if money is important to you there are almost certainly combinations which will save you truckloads of cash.

Use Oebb.at which is the Austrian national trains to find a Sparscheine (discount) ticket from Innsbruck to Zürich for 19€ each.

I don't know your travel days.

I used https://www.oebb.at/en/tickets-kundenkarten/oesterreich-europa/sparschiene.html which is in English and set up for the discount page. Walk up prices cost significantly more.

If these deals interest you let us know and we can help.

Not sure how you got USD 158 for Innsbruck to Zürich. I would expect the DB site to quite in Euro, not USD.
DB = Deutsche Bahn= German Railways. Innsbruck to Zürich doesn't go via Germany, it is a joint service by ÖBB and SBB (Austrian and Swiss Railways).
Were you perhaps looking at the price for today? In order to get the price I quoted €19 per person) you need to buy the tickets about 2 months in advance.

"We are also traveling around southern Bavaria for a few days" - you need to know about the "Bayern ticket". This is a one day for the whole of Bavaria.
It covers all public transport in Bavaria, not just trains but city transport (U-Bahn) and buses as well.
Two restrictions: It is valid from 09:00 on weekdays, all day at weekends. And it is not valid on High Speed trains (ICE, IC), just on "Regional" trains.
The best bit, cost €25/day for one person, €32 per day for two people.
You can buy it from an DB ticket machine in Bavaria.

Details here: https://www.bahn.com/en/view/offers/regional/regional-day-ticket-for-bavaria.shtml

When is your trip?

You can use the Regio-Ticket Werdenfels Plus Innsbruck ticket for two persons, Munich > Innsbruck (€39.) It's similar to the Bayern Ticket - you buy at the station in Munich - but it's better since it's valid before 9 am, and it gets you all the way to Innsbruck.

Then do the OEBB ticket previously mentioned for Innsbruck > Zurich.

Thank you all for information shared!