Lots of hotels in Sultanahmet have rooftop restaurants with nice views, though I think the best of them is the Hotel Seven Hills, which has a 360 degree panoramic view of the Bosphorus and Sultanahmet. Unfortunately, the food there is mediocre and overpriced. I'd have a long lingering drink there, enjoy the view, maybe have some mezes, and eat somewhere else afterward.
Wine is available in most restaurants in Istanbul, though there are a few without alcohol. But foreign wine is crazy-expensive due to duty levied on it, and Turkish wine is not cheap, either, especially given its not so terrific quality. The two most commonly available wines are from the wineries of Doluca and Kavaklidere, and most of what you will find of their wine is low level vin de table. We did get some better wine occasionally--Turasan was particularly nice--and some godawful swill, too--Pamukkale is a brand to watch out for. And both Doluca and Kavaklidere make some higher end wines, though they aren't often found in most restaurants.
Wine is not likely to be a highlight of your Turkish food experience. We drink wine nearly everyday with dinner at home, but in Turkey, most of the time I stick with bottled water or beer.
