Based on reviews here I called Tino and he accommodated us out of the blue. Turns out he's usually only open in the winter. Certainly a unique experience, and quite a hike UP from Wengen. The salad and cheese fondue were excellent, but pricey at 41 CHF pp. We aren't big drinkers but agreed to "some wine" and had much less than half a bottle. My mistake for not realizing we'd be charged for the whole bottle. He also suggested "kirsch", which we accepted, though only tasted it on a couple pieces of bread. That too was an additional charge, as was water of course.
Tino had interesting stories, and we had an enjoyable evening. Everything in Switzerland is expensive, and it's my fault we ended up at 300 CHF for 6 people, instead of the 250 we started with.
Go for the experience, but if you just want to try swiss fondue, probably get it in town, or better yet make it yourself.