Be careful when booking a tour in Tuscany, especially wine or bike tours or others where travel is involved. There are lots of tour operators that seem "official" because they have a great website or brochure (and even lots of nice reviews here!) but are not licensed and do not have insurance to cover you if something should happen. Lately there has been talk in the Italian press about how the government is starting to crack down on these "abusive" tour operators. One offering wine tours was fined 1,600 Euros and asked to cease operations and another was stopped during a bike tour and all the tourists were left stranded in the countryside because the Italian carabinieri (policemen) impounded the bikes and vans mid-tour!
Just ask your tour operator for proof of insurance and license, check if they're a member of a tour operator association...it's common sense and as simple as that, and might save you lots of money if something should happen and you need medical care.