I suggest combining this tour along with a Chianti area.
San Gimignano in fact is famouse for a typical Tuscan white wine named Vernaccia di San Gimignano and Chianti is famouse for the reds.
On request it is possible to include a visit to local oil mill or to producers of other typical products, in accordance with the wishes of visitors.
My family wanted to book a wine tour and most companies only offer up to 8 people but we had 9. We also wanted to be able to taste some white wines and not all reds knowing Tuscany is famous for its Chianti. I emailed Italy and Wine and they were so accommodating to our requests and our guide, Ingrid, was so informative about the history of San Gimignano. We not only enjoyed the wines and the vineyards but also loved our time exploring San Gimignano. We all wished we had more time there! Also, the lunch we were served at the first winery was amazing. The food just kept coming out and they paired each course with a different wine. Overall, a great experience! Highly recommended!