We just returned from a trip celebrating my in-law's 50th anniversary. I pre-ordered a cake from 1900 Park Fare in the GF for our dinner there, and they gave them the royal treatment! I also mentioned it to the CM taking PS reservations, asking who to order the cake from, and I think that he put it on the system. They had balloons, chocolates and a signed card from the WL the first evening there.
When you call, mention that you want to do something special for your spouse for your anniversary while you're there, and see what they mention. It doesn't hurt to ask!