At GABF a few years ago, Blue Moon had several flavored variations and one of them was a white wine grape. I think it was reisling, but I'm not sure. I remember liking it, but i remember many, many, many samples before it.
DFH has a few beers with wine flavors, Noble Rot, Midas Touch, i'm forgetting another...
Either way, adding grape juice to a beer is going to give you more wine-like flavors than just using a wine yeast.