Wineries typically show up first in Google searches for their brand (having the winery name in the URL is key for this), but for more specific searches, often lose out to retailers or other sites. Owning that top spot is key, as shown in this heat-map of user click behavior: The top result receives over 50% of the clicks.
It is even possible to own two sequential spots on Google, but it's rare and typically limited to similar products or parent/child classes of products in larger database-driven sites:
Retailers and wineries do have another ace at their disposal, though, and it’s Google Products (formerly known as Google Base). As can be seen in the screenshot below, Google now shows shopping results in the main listings. Coupled with an image, this is a very attention-grabbing part of the page, and I would expect the heat-map distribution to change based on this new page design.
As a winery or retailer, you should make sure your products are listed in Google Product Search -- instructions can be found here -- whether it’s something you do yourself, or a service your website management company can provide, this should be a priority. It’s free, it's Google, the searches are targeted, the users are highly qualified, and some other wine sites (including WineLog) even populate their database using Google’s data, so the reach is further extended.