Here are some resources and articles on non-corporate wine for you. Other terms you might want to search for, should you wish to delve further, are "socially responsible," "fair trade," "organic," "biodynamic," and some phrase with the word "family."
A good starting (and finishing, even) place is Co-op America's National Green Pages, where you can select the category "Wine/Beer" and click search. As of 5/24/07, there are 14 results (some of which are listed elsewhere in this answer).
Co-op America also has an article from February 2007 on fair trade wine. Mentioned there is Etica, which distributes fair trade wine, both reds and whites.
Frey Vineyards claims to be "the oldest (since 1980) and largest purely organic winery in the United States, family owned and operated from the start."
Organic & Sustainable Wine Production Expanding Rapidly in California is an article reprinted on the Organic Consumers Association website. One winery discussed is "Coturri Winery in Glen Ellen[, which] boasts 370 acres of organically certified vines. It has long been considered one of the local vanguards of environmentally and socially conscious winemaking." The Viansa and Benziger vineyards are also mentioned.
Another resource for non-corporate U.S. wines is the Family Winemakers of California (though, judging by their 2006 tasting sponsor list, they are certainly corporation-friendly). Check out their member list of wineries.
A search in the Academic Search Premier database (likely available through your local public library) found the following articles that should also point you in some good directions:
Title: VIRTUOUS VINO.
Authors: McLaughlin, Lisa
Source: Time; 3/5/2007, Vol. 169 Issue 10, p76-76, 3/4p, 2c
Abstract: This article reports on the label of biodynamic as it applies to wine. Biodynamic farming is a combination of organic farming and numinous practices like harvesting according to the location of moon in the sky. One biodynamic vintner claims that playing Mozart helps his vines to grow. The author alleges that organic wine is better for the planet and a healthier alternative for wine drinkers. Organic vintners such as Dinaube Marcel Deiss of Alsace and Emindo Pepe are mentioned.
Covers, rather snarkily (well, it's a mainstream publication), the latest efforts in organic and biodynamic winemaking.
Title: A Fine Nose for The Family Business.
Authors: Schine, Eric
Source: Business Week; 1/8/2007 Issue 4016, p66-68, 2p, 1c
Abstract: The article discusses the winemaker Maison Joseph Drouhin, which has succeeded as a family-run vintner through four generations. Despite financial and political pressures to sell their vineyard to outside investors, the Drouhins, overseen by patriarch Robert Drouhin, have worked hard to run the organization as a family and compete with a globalized corporate market.
Title: Organic Grapes, Organic Wine.
Authors: Gleason, Paul
Source: E Magazine: The Environmental Magazine; Nov/Dec2006, Vol. 17 Issue 6, p34-39, 6p
More about organic winemaking and labeling issues.
Title: A Family of Vintners.
Authors: Rice Lamb, Yanick
Source: Essence; Oct2003, Vol. 34 Issue 6, p208-213, 4p, 2c
Profiles the Browns, an African-American family that owns a winery in Northern California. An inset lists other African-American vintners in California.
And, in case you're now highly interested in environmental aspects of winemaking:
Title: Terroir.
Source: New Scientist; 2/24/2007, Vol. 193 Issue 2592, p54-54, 1/2p, 1c
Abstract: The article focuses on the concept of "terroir" in wine-making. Terroir traditionally refers to a geographic region and its microclimate. Oenologists and viticulturists who advocate a broader definition say terroir should reflect other factors including cultivation method, the fruit itself, and production of the wine.
