Do you show one of your wines on your home page? Then see if this question from the 37signals blog applies to your site:
Why would any retail Web site feature a product on its homepage without allowing a site visitor to quickly and easily buy, or at the very least, learn more about that product?
The question caught my eye because one of the recommended best practices in The Winery Web Site Report is featuring one of your wines on your home page, linked directly to a page which provides the information a visitor needs to make a decision to purchase the wine quickly and easily (online or offline).
Emphasizing this same line of thought is a free 12-page report from 37signals: Sites That Don’t Click: Homepages that Leave Prospective Customers Hanging (PDF - 900 Kbytes). It provides ten examples from retail Web sites, and offers three concrete suggestions for your own home page. Although the report doesn't include any winery Web sites, you'll see similarities between the image-intensive way retailers present clothes and electronics and the way some wineries present their wines.
An important concept in designing effective Web sites is to maintain your visitor's expectation. If you show a specific wine on your home page, clicking that image should take you to a page specifically about that wine (not your entire catalog).