Bonterra Vineyards has some vegan options

Company email (May 2018)
"I realized that on your website says that the Sauvignon Blanc is the only vegan wine that Bonterra has, I want to clarify that, and tell you that all our whites are Vegan so that's include Bonterra Chardonnay, Bonterra Viognier, Bonterra Rose and of course Bonterra Sauvignon Blanc."

Company email (November 2016):
"Bonterra Sauvignon Blanc is the only wine which is consistently vegan friendly."

Company email (January 2013):
"All of our white wines are vegan. All of our reds are fined with egg whites, so they are not. None are processed anywhere else other than our winery in Hopland which is certified organic (not that that really matters for this specific question)."

Company email (December 2012):
"In response, while we do offer our various product lists, some products in our stores and the selections offered may actually vary somewhat by state and region. The primary reason for this is that we also attempt to source products locally whenever we can, as we also do not ship our products over really long distances. Our lists are also not all-inclusive, and are offered moreso as a guideline of possible product selections.

In response, to your inquiry regarding our possible vegan wine options, we are enclosing a list of possible vegan wine selections below:

Bonterra-Whites are vegan
Castle Rock-All are vegan
Charles Shaw-Reds are vegan *occasionally gelatin is used in the whites' refining processes, but that it is removed from the end product
Cline Cellars-All are vegan
Fetzer-Whites are vegan
Georges Dubeouf-All are vegan
Kendall Jackson-Whites are vegan
Rosenblum Cellars-All are vegan"

Our previous entry was based on feedback from a restaurant, but Jenna set us straight - it's always best to go to the source:
"One of the wine companies most widely known to be vegan, Bonterra, actually uses egg whites in their fining. You should take them off your wine list and even consider running a blurb - Native Foods, Herbivore, and a ton of other vegan restaurants sell or have sold them, and tons of vegans I know like to drink it. Their white wines are vegan, but their red wines are NOT. I just got off the phone with James Caudill, one of their reps, and he confirmed it."

Seconded by Mo - company email:
"We use egg whites in the fining process of our red wines. However, our white wines are free of any animal products and are vegetarian and vegan friendly. Ages ago, it was discovered that egg whites added to wine would aid in removing unwanted tannins. This 'tannin fining' process is used to improve the flavor of red wines by limiting the astringency caused by the tannins. The egg whites settle to the bottom and are then filtered out. All residue of the egg whites is removed from the wine."