Another request for help on which is best pass?

Welcome Ron and Cate! Deciding which rail pass to choose can be difficult indeed. The Swiss Card is definitely worth considering, as it provides a free trip from Zurich Airport to Wengen and back, and a 50% discount on nearly all other trips you may want to make during your stay in the Bernese Oberland. If you plan to make rather short trips when staying in Wengen, this might be a good option.

A good alternative would be the Regional-Pass Bernese Oberland, providing discounts and some free travel days on top of that. It can be purchased from the Regional-Pass Bernese Oberland page if you wish. Since the free travel days are the major advantage of the Regional-Pass, this pass would come in handy if you plan some days with intensive traveling, including several mountain trains and cable cars. Part of the trip from and to Zurich Airport is covered too.

Which pass will turn out to be the most economical, can only be discovered by making detailed calculations based on a very exact list of your plans. If you don't have such a list yet, you'll have to make a reasonable guess. But both the Swiss Card and the Regional-Pass will save you lots of money, that's for sure.

As for regular (discounted) tickets for your trips: you can order them online in advance, but you can also choose to buy your tickets at the spot before boarding a train or cable car. This will allow you to adapt your plans to weather circumstances.

I hope this gets you started!