Taking the high speed train to florence. Then, not sure how to get to chianti, Staying in a farmhouse for 2 nights
where exactly in th Chianti region and have you asked the farmhouse where you are staying if they have a shuttle service? Have you thought about renting a car?
We are staying in a farmhouse in radda & they don't offer a shuttle
If you stay in a farmhouse, you will certainly need a rental car. They are all in the middle of the countryside, often too far to walk from the closest town. Buses are not frequent, even assuming your farmhouse is in a road with bus service. Book a car in Florence.
www.autoeurope.com
Rental car
A corkscrew and a couple of glasses has never failed to get me through a chianti.
But as the others have said, farms aren't well served by public transport. Rent a car. Enjoy countryside driving.
We took the train from Florence to Siena and got a car at Hertz. Train station and nearby Hertz are in outskirts and it was not difficult to get into the country where we found driving pretty easy as long as we stayed outside the walls of the hill towns. Yes, they tailgate. Be alert on the mostly narrow roads with no shoulder. Even though Hertz is close to station, area is not pedestrian friendly so a taxi is a good idea if you choose this rental place. You can take an escalator up to Siena from the train station. As others say, car is necessary in most cases once you are out of the cities in Chianti and all of Tuscany.