I think you will find local quality food pretty much all over Venice. I don't think you mean homemade wine.

There are many wine shops that have local wine that is sold by the liter out of giant casks. Get an empty liter bottle of water and use that to fill up in.

I generally stay in Castello, but have stayed in the general San Marco area, but not near the square.

Let me know when you find a non-tourist area in Venice. I've yet to find it, unless you go by the commercial ship docks.

All of the 6 areas (sestieri) on the main islands have their touristy & non-touristy spots. I live in the sestiere of San Marco (but not near the Piazza) and even here it's easy to escape from the hordes. All areas also have good & bad restaurants, and local bars.

Cannaregio & Santa Croce have the fewest tourist hotspots but also have a higher proportion of charmless areas IMO. The eastern part of Castello, round the Arsenale, is quite 'local' and non-touristy but doesn't have a large number of restaurants.

(How's your Italian, btw?)

Not sure what you mean by homemade wine - I don't think bars & restaurants would be allowed to sell actual homemade wine. No wine is commercially made in the city itself because, well, it's a city. There is a bit made on the islands of Sant'Erasmo and Mazzorbo but it's not easy to find; I don't think the Sant'Erasmo wine is great quality hence not found in restaurants/bars, and the Mazzorbo wine while higher quality is made in very small quantities & accordingly priced - I saw it listed in a restaurant we were at last week for something like E150 a bottle. La Cantina on the Strada Nuova, while on a fairly grotty, touristy main drag, is a decent wine bar which makes its own very good beer, however.

There are plenty of interests wines from the Veneto region in general, though, many using grapes you don't find elsewhere like Raboso and Refosco.

You have to be careful about restaurants in Venice. A lot are of poor quality, for tourists only. Research ahead of time and NEVER go in a restaurant with a tout outside.

As long as you stay in Venice proper, not Mestre, not the Lido, and avoid hotels near Piazza San Marco and the Rialto, you should have a good experience. There are quiet neighborhoods and almost empty squares just a few feet from busy tourist-trodden walkways.

I highly recommend the Cannaregio. Lovely area. If you stay between the Strada Nuova and the lagoon-side, you can catch the vaporetto that go directly to the different islands.

Lots of places to eat/shop, yet can be very quiet and lovely.

PS I should have mentioned that you can catch those vaporetti at other stops, including Piazzale Roma. But there are a number of vaporetti that stop at the Fondamente Nove vaporetto stop that take you directly out to the islands.

I adore the Dorsoduro area of Venice. It is quiet, lovely and convenient to everything else.

We aren't much help, are we?

The Dorsoduro area is very nice and has restaurants that are not aimed at tourists. Another thing to look out for is a multilingual menu. However, we went to a restaurant not far from San Marco and refused to be ushered to sit outside. That was obviously the tourist area with multilingual menus. We went inside and sat with locals including a large group of builders. The menu inside was in Italian only and fixed price.
We stayed in a flat behind the Arsenale early this year. It was a residential area and we soon found our favourite little shops. We also used the little supermarket in the Via Garibaldi.
It certainly helped being able to speak some Italian.

We've just returned from a week in Venice, staying in an apartment on the Cannaregio Canal.

We love this area - it's the second time we've stayed here. Some good local restaurants, local shops, including a wine merchant, good vaporetto service.

What me didn't enjoy was having to wade through about a foot of water (no boardwalks on the Cannaregio Canal) to get to the station because of the acqua alta on the day we were leaving, CARRYING our luggage as high a possible to keep it out of the water, not always successfully. The vaporettos stop running between Guglie and Tre Archi bridges, so walking was the only obvious option. Not fun, but it could have been avoided if we were more vigilant, and informed ourselves better!

All restaurants that have tourists are bad????

You are telling me that the restaurant with the "obvious tourist" area outside served entirely different food than was served in the "non obvious tourist" inside where apparently tourists still can eat?