I might be a little late for this thread (but I just found it).
My dh & I went to WDW in may to celebrate our 15th anniversary. Someone suggestioned to me to mention to everyone we met (cast members in particular) why were at WDW and it was great. On our first day at MK we came across a photopass CM and we mentioned to hm we were celebrating our anniversary. He sent us to the Town Hall and we got pins that said "Magical Wishes" and had a Mickey & Minnie (as a bride & groom) on it. We wore them every day we were there and everyone (CMs & characters - like Snow White, Alladdin & Jasmine, Mary Poppins & Alice in Wonderland to name a few) all congratulated us.
At Epcot while we were waiting to eat at the restaurant in the Canadien pavilion, we received a call from Mickey & Minnie congratulating us on our anniversary too.
Also, we stayed at Ft. Wilderness Resort & Campgrounds and one night at dinner at the Tavern our waitress surprised us with a certificate entitled "certifiable magical moment" and a strawberry shortcake for two in honor of our anniversary.
So my advice is tell EVERYONE!
hugs,