We are planning a special event for a friend in September 2010 and are looking for a winery in either Sonoma or Napa that could provide lodging for a group of 8-12. Any recommendations? I have started doing research and haven't found much. Any advice is appreciated.

You could try the Silver Rose Inn in Calistoga although it might be more commercial than what you are looking for.

http://www.silverrose.com/

RustRidge is a nice winery b&b just east of the Napa Valley but they probably don't have enough rooms. You could call them and maybe they could refer you to a better option.

http://www.rustridge.com/

Why do you need to be staying at a winery?

We've stayed many times at the Milat Winery http://www.milat.com/ a very small winery on Hwy 29 in Napa Valley.

We're staying one night at Beltane Ranch in Sonoma. Not at a winery but a working ranch in the middle of a vineyard:
http://www.beltaneranch.com/

Not a winery, but Westerbeke Ranch in Sonoma outskirts is a lovely, secluded place for a special event; has great food. Used as a small meeting.conference center.

I stand corrected. Beltane Ranch has bottled their private label sauvignon blanc this month and it will be available later this spring.

http://www.beltaneranch.com/news.html

Beltane Ranch looks really nice, it's pretty reasonably priced, also. ***kim***

Cliff Lede has the Poetry Inn, but the inn is not located at their winery.

www.poetryinn.com

Sept is a very busy time in the wine region. Some of the places listed above are good choices, but my guess is that most or all of them are already partially booked up for your time.

So if you need to sleep 12 you need to book ASAP -- and will probably need to contact several places before finding enough availability at any one property.

Thank you all for the wonderful suggestions! I will be making a ton of calls tomorrow. And Beltane Ranch looks fantastic especially for the price. How have I missed this place on my trips to Sonoma???

With summer coming I thought I'd bump this with some information about the Wilson Winery "Artisans Group" and the lodging they offer.
I think that there are 7 wineries in the group now, and at least DeLorimier, Mazzocco, St. Anne's Crossing,Jaxon,Soda Rock and Pezzi King have lodging. the group also operates 2 Inns- the Calderwood Inn and The GrapeLeaf Inn in healdsburg.

Other wineries that I know of that have lodging avilable to the public are Cline, Landmark,and Little Vineyards. I'm sure there are others....