6 days between venice and florence on train.

trust me, you can get red wine EVERYWHERE in Italy, and I'm sure there are lots of places that offer tastings. I did not do a winery tour in Italy, but in July my friends and I did 2 days Florence, 2 days to Varenna on lake Como, (changed trains in Milan) and 2 days in Venice, all on the train. beautiful scenery, amazing food, and plenty of wine and gelato!! housing, train tickets and food averaged about 100 euros per day including a few museum admissions

Reading one of the replies and am wondering how you do two days in a city on a train, particularly Venice? thank you for the explanation.

I'm not clear either on the OP's timing. Leaving Venice and arriving Florence 6 days later? The Veneto has lots of good reds, Bardolino and Valpolicella come to mind. These are both in the area immediately east of Lake Garda, north of Verona. They will of course, be available in Venice. In Florence, its Tuscany and you have all the classic Tuscan wines, like Chianti and much, much more.
We went to a fun wine tasting in Venice 4 years ago explaining the Veneto wines, but when we returned 2 years later, we found out the owner sold out (probably laying on a beach in Brazil now) and the place is now just another run-of-the-mill Venice tourist restaurant. So keep your eyes open and see if something similar is being done elsewhere in Venice.

As was correctly reminded, you can have red wines everywhere in Italy - just walk to the closest bar.

But while there are large producing areas south of Florence, around Verona and north-east of Venice, the places on the direct path are not known for their wines - the mountains between Florence and Bologna are too cold, and the plain between Bologna and Venezia better suited to industrial farming.

There is usually red wine available on the trains at the Freccia and Italo level.

liz, I meant that we did not rent a car, which is how I read OP's question....what can she do that is accessed by mass transit.....

I take it as though you mean you have 6 days between the 2 cities and will be traveling between them by train... Assuming that is correct I would suggest 3 days in each location. I took a number of little wine tours last Oct. from Florence and they were great fun. Every hotel will have brochures for bus or train wine tasting/sightseeing tours. I just hopped on a few that were available the time I wanted to go. With only a few days in Venice I would just spend my time there drinking wine rather than leaving.... maybe a day trip to Burano. But, everywhere you go in Italy you will have wine and gelato:)

We had a wonderful 2 days in Veronna between Florence and Venice and would recommend it as a stop for great gelato, wine and food. We did not do a wine tour but enjoyed tasting at wine shops and especially enjoyed the gardens. http://www.gardenvisit.com/garden/giusti_giardino