I don't know if you think that your winery business makes you a "retailer", but in some sense, you are (at least if you're part of the vast majority of wineries that produce fewer than 5,000 cases a year). Your business depends on selling directly to the people who know and love your wines. And for retailers, Christmas is *the* high season.
Your wines will make a great holiday gift, both personal or for business. Are you emphasizing that fact on your Web site (like on the home page)? Are you making it easy for your fans to spread the word about your wine by giving it as a gift? "Easy" means both clear and simple instructions on how to make it happen, as well as a nice selection of gift offerings, and recognition of the fact that this is a gift (wrapping and a gift card).
And remember, this doesn't mean a huge e-commerce effort - a nicely designed page with effective copy and an 800-number that shows how much you want to help solve people's gift-giving dilemmas will probably do more for you than a sterile online shopping cart approach.
Every other retailer in the universe knows that Christmas is fast approaching, and is taking appropriate action. You should be, too. It's a once-a-year chance to leverage the gift-giving good will of your current fans to introduce people to your wines. Don't miss it!
PS - Do you have an easy-to-update home page so that you can communicate special messages to your visitors throughout the year? If not, make that your New Year's Resolution.
PPS - Please feel free to add examples of wineries doing Christmas retailing on their Web sites to the comments.