I have had PVCs for a couple of decades now, and have never found a real 'trigger,' other than maybe possibly perhaps a change of seasons. I did give up coffee, but frankly, on the rare occasions I drink it, I don't notice any change in PVC frequency. In fact, I have a growing suspicion that there are very few real triggers for these things, even though people knock themselves out trying to find something, anything, that is responsible and easily fixable.
I love good wines and have two glasses a day, and this does not seem to make any difference at all. Assuming you are otherwise in good health and that your PVCs are benign, a modest amount of alcohol is probably not harmful.
But moderation, as seaweib says, is the key, with or without PVCs.
I think alot of it depends on how much you drink. Lots of people (including doctors) say that alcohol can contribute to PVCs. Considering that PVCs are a generally benign condition though, if you can handle increased PVCs, you're probably ok drinking.
I was diagnosed with PVCs and used to be a pretty heavy social drinker. Docs said not to worry and I kept drinking. Then 8 years later was diagnosed with PACs and soon thereafter I had a short bout of afib. Needless to say, I've cut back on drinking since that happened.
Point being, if you have a healthy heart, most of what I've read and been told points to it being fine to drink in moderation. For people with skipped beats though, binge drinking is probably not such a good idea.