There is no bus to Fantasia Gardens. One must find transportation to the Swan, and walk across the street. (You can get to the Swan vai bus from MK, AK or DTD, or via boat from the Studios and World Showcase)
To get to Winter Summerland, you need to take a bus that goes to Blizzard Beach. Currently, Blizzard Beach is closed. The only bus that runs to Blizzard is the Coronado Springs bus from Epcot. This bus runs 365 days a year, until 8:45pm nightly.