As an Ex-Wurzburger I commend you on your choice of towns. If were you I would drink enough of the big .25L glasses wine and do away with the need for dinner at all. However if you lead a more sober lifestyle than me then I can recommend a few places.
Bella Napoli, Neubaustr. (close to the old bridge), I know you said you have had enough Italian, but this is simply the best Italian food I have ever had, including when in Italy. If you go, tell Mimi that Robert said hi (not my name, but due to a misunderstanding it is now my name there).
Julispital, JuliusPromenade. Good German food and usually fresh fish. They also have some great wines.
The aformentioned AlteBrucke MainMuhle, on the old bridge. Good food and really good Spatburgunder. This is a good one to save for the summer when you sit out on the balcony that hangs over the bridge.
Backofele, in an alley near the old bridge (ask someone). Great German food, but not alot of veggie dishes. However if your travel partner eats meat, tell them to get the Schweinruckensteak (the one with mushrooms). Also this places has the best bratkartoffeln.
If you go tour a winery go to the Burgerspital and see the 500ish year old bottle of wine they have there, the StaatlicherHofKeller is also and good tour. Go to the Festung on the hill. Have a good trip and feel free to PM any questions.
Edit:
Stay away from the beer, it sucks compared the rest of the country, but did I mention that the wine is good? However if you must have beer there is only one place to go that has a few good ones including Kreuzberger and if you havent been to
Kreuzberg you should seriously consider a trip sometime.