You will certainly be able to use the gift card for drinks and tips at all restaurants at the Disney resorts (but not those at Swan and Dolphin). I have never done the DDP, but it doesn't seem to me that being on the DDP would change that answer.
My DH called and asked the same question. He was told that you could use the card for tips/drinks everywhere except the Swan and Dolphin. We're planning to use ours for tips.
We are on the QSDP but are going to use the giftcard for a dinner at a TS restaurant. There is a link from the disney site with the advertisement for the $200 giftcard that delineates what the gift card can be used for and so long as it is Disney owned you are pretty much okay. You just can't buy another gift card with it (sound weird anyway) or get disney dollars for it if I am not mistaken. I was also told that if you charge stuff to your room the extras can be paid for with the gift card also.