MarketingSherpa.com has a great case study about a retail wine store that doesn't sell online or ship wine (!!) using its e-mail newsletter to bring in a lot of (paying) foot traffic. You should be able to use the same tactics to bring folks to visit your winery (or get them to buy online or over the phone and have it shipped). After all, your winery is a lot more interesting than a retail wine shop, isn't it ? The article is free through June 4th, so print a copy if you want to save it.
Here's another MarketingSherpa.com article of possible interest: How to Keep Your House List Open Rate Above 50%: Lessons from Winery Email Campaigns (October, 2003). Unfortunately, this article will cost you a token $5, but given the consistently high quality of their case studies, I recommend it (I already purchased a copy for myself).
As always, I recommend MarketingSherpa's free newsletters (signup at top-center).