A group needs only two things to be a tribe: a shared interest and a way to communicate.
The key for wineries is that your 1,000 True Fans (and even those who aren't True Fans but still like your wines) can be a tribe. The shared interest is already present: your wines. You should be thinking about how to help your tribe to communicate.
Best of all for busy winery owners, it's a short book (and you can get the audio book on iTunes for 99 cents, or for free if you register for Audible.com).