As a sidenote, the only government-run enoteca in Italy is based in Siena at the Fortezza Medicea. Tel. + 39-0577-28.84.97
It is FANTASTIC and has an English-speaking staff. Unfortunately, I recently received an email stating that they are no longer able to ship to the U.S. (maybe has resumed?) but it is WORTH a trip there if you are in Tuscany (and don't miss the Duomo there).