Jun 13, 2017 - 2:13 AM
in reply to OHGeologist
Yes, your Swiss Travel Pass Flex (completed for a travel day) and your seat reservations are all you will need.
When you board the bus, the driver will have your name on a list, so just tell him or her your name. You probably won't have to show your reservation.
Seats are not allocated, so you can sit wherever you like. The descent into Menaggio is quite something, and the skill of the bus driver will impress you!