If you’re going to Wengen for 6 nights, it doesn’t make sense to get the Jungfrau Travel Pass for only 3 days.
Also, I’d suggest rethinking your idea of seeing Lake Geneva, Zermatt and Bern from Wengen. Those are really long day trips. Bern is an ok day trip from Luzern if you have just so so weather.
There is so much to do in the Jungfrau region without going so far every day. There are 2 lakes way more convenient (and way prettier) in Lake Brienz and Lake Thun right where you are without going all the way to Geneva. Plus Lake Thun has 3 castles right there to see and on Lake Brienz you can go to the Ballenberg Open Air Museum. Zermatt has the Matterhorn, but there are a ton of places around the Jungfrau region where you can go up to see stunning mountain views without taking a really long day to go to Zermatt just to see a specific shaped mountain (Schilthorn, Jungfraujoch, Schynige Platte, Mannlichen, First, Allmendhubel, Brienzer Rothorn, Niederhorn, Harder Kulm, etc. etc.) You absolutely will not get bored exploring the region without such long day trips.
Anyway, al that to say, I’d get Half Fare Cards + the 6 day “Adults reduced” Jungfrau Travel Pass OR Half Fare Cards + the 6 or 8 day “Reduced Fare 1/2” Berner Oberland Pass. Either of these options is going to be better for you than the Swiss Travel Pass, where you’re going to have to be buying a ton of supplement tickets for the mountains. Deciding between the BO pass vs the JTP depends on which specific activities you plan to do. Look at the validity maps to decide what the best fit is for your plans.