We just heard back from Palazzo Antellesi that they could provide a mini van from the airport in Bologna to the Pallazo for €160. We haven't heard back from either of the other companies we tried to contact about this, so we went ahead and confirmed the ride with the Palazzo. At about $200 door to door it seems well worth it - remember we have two small children and will probably have 12 pieces of luggage. This cuts out the bus ride to the train station in Bologna, and then the taxi ride to the Palazzo from the station in Florence.
Anthony