Tom, The Google offers a few tantalizing hints, including the factoid that 2 percent of El Dorado's production is in the category "Fruit / Vegetable Wines." It all seems to be apple wine, though, from Stone's Throw winery and others; I couldn't dig up any specifics on a veggie wine, though, and don't recall ever running into any such in the Golden State.
I can testify, tangentially, that I've judged tomato wines in home-wine judging i Kentucky and Maryland. In both instances it was a clear, white, nearly-dry wine with a neutral fruit character, not bad but certainly void of either varietal character or terroir.
