Bees do not work grapes, which are wind pollinated. If the vineyard has a "mow strip" between vines, these produce some spring (weed) forage. Bee's forage over multiple kilometers, so the countryside resources is as important as the local. There is a time/energy/bee loss cost to forcing bees to travel even a kilometer for the first forage. Many vineyards are heavily treated with fungicides and insecticides. Bees are sometimes implicated in feeding on overripe or windfall grapes during the fall dearth, but these grapes are either opened by yellow jackets (which will bore through the skin, or the grapes split naturally).
In general, vineyards are poor choices, because they are not a forage source and present chemical risks. They are generally heavily protected from animals and human intruders, so if you live in bear country, that 's a plus.
