Restaurants in DtD, no. None of the restaurants at DtD are owned by Disney and the gift cards only work at Disney owned locations. In DtD, you can use Disney gift cards at the candy shop Marceline's and at the Disney owned retail stores. Gift cards should work at whatever restaurants are open in Disneyland Hotel or The Grand Californian Hotel since they are owned and operated by Disney.
No problem using Disney gift cards in the Disney hotels. I used one for mobile orders at the Coffee Shop and Tangeroa Terrace at DLH, and for breakfast at Storyteller's Cafe.
But they were not accepted at either Tortilla Jos or Ralph Brennan's.