We stayed five nights at Tenaya lodge in September for a wedding. The wedding ceremony was held offsite and the reception and dancing were back at the resort. It took place on the Terrace (a big beautiful outdoor space) and it was a lovely dinner with a big dance floor. We moved to the ballroom at 10PM and got to party and dance and drink all night, it was fabulous.
The staff, for the most part, were very helpful and enthusiastic, but for what we paid it wasn't really worth it. The food is not very good and VERY overpriced, you're better off stopping at Vons on the way in and getting snacks, water and alcohol to sustain you. We ordered room service several times and had to call down for items that were missing (spoons for coffee, extra set ups, salt + pepper, etc.) Drink the free coffee in the room instead of ordering from the deli downstairs, it's the same stuff as in the restaurants.
Showers would go from hot to cold unexpectedly. The rooms aren't very big and feel pretty dated.
The pool was nice and while I didn't get any spa treatments, you can use the steam room and the sauna whenever you like and relax in the lounge.
If you want to splurge and spend money on a hotel in Yosemite, it's best to go somewhere inside the park. Otherwise there were some cute inns and cabins along the way. If you do stay at Tenaya there are lots of discounts available at places in and around the park (20% off at Bass lake, 15% off gift shops at hotels inside the park, etc.)