There are many wineries, some big ones, in Beamsville, all within a short drive of one another. I'm in Grimsby, so just up the road. I've not done any official 'tours' but I have visited many. Tawse, Megalomaniac are two of the largest, Redstone, Malivoire, Bench are in the same general area. My daughter worked at Redstone a few summers, it's very nice.
The wineries generally start at the Grimsby/Beamsville border with Peninsula Ridge, then you travel east on Hwy 8 all the way into Jordon if you're so inclined.