Here's a post about how long it took some wineries to respond to an e-mail query about whether a particular bottle was ready to drink. The wineries involved were Tobin James Cellars, Grgich Hills Estate, and Frank Family Vineyards. Response time varied from 90 minutes to over four days. Not a scientific test, but surely an interesting result.
(as a side note, Grgich prominently mentions their Facebook group on their home page)