Montalcino/ Montepulciano

Planning a day trip to Montalcino.

From where? And what form of transport will you be taking to get to the wineries?

I know two wineries there: La Ragnaie and, my favorite, Ventolaio. Ventolaio has some of the best Brunello for the price I've ever tasted.

There is also a huge shop near the main piazza where you can taste about 100 wines (good luck!). They ship.

Staying at the Borgo Alle Vigne, planning to drive to Montepulciano & Montalcino.
Would to check out some good wineries in the area.
Any recommendations?
Is it feasible to include Sienna in this Itinerary or is it too much in one day?
I heard there are some hot spring near Sienna?
I can make this a 2 day tour if possible?

Thanks for any suggestions you may offer.

You definitely CANNOT see all three cities in one day. You can manage Montalcino and Montepulciano in one day although your stay in each will be very brief. In one day you can get a brief overview of Siena but anything less would be meaningless.

We visited two great wineries, both require reservations which can be made by phone or email.
Altesino (http://www.altesino.it/ita/azienda.php) and Santa Giulia Winery (http://www.santagiuliamontalcino.it/brunello-wine-producer/). Altesino is a larger winery with a great tour and tasting. Santa Giulia is a small, limited production, family run winery that also is a working farm. At Santa Giulia we took a tour of the grounds, then had a tasting with a huge spread of food from the farm. It was magical! And both wineries were very warm and friendly. It was a relaxing day to visit both AND the town of Montalcino (with two teenagers in tow.)