AA,
There are several types of viticulture that employ "organic" methods. Unfortunately, because of the strict labeling requirements for the word, "organic," in the USA, few wineries here that are using organic methods are going to put the word on the label. Mostly, it has to do with the farmer wanting to reserve the right to spray the vineyards if there is some toxic mold that threatens the entire crop, or some pest. For the most part, organic methods are taking hold in CA, OR and WA. Rows of grapes are planted further apart, and "cover crops" are planted in between that discourage the types of pests that can afflict the vineyard, plus promotes greater air circulation around the bunches of grapes to inhibit mold.
In Europe primarily, there are a number of biodynamic farmers who practice what I think of as "organic+". Here is a link to a website on biodynamics if you want more info:
http://www.biodynamics.com/
The best way to determine whether a wine is made by organic methods is to look the winery up on the internet.
Hopeful