Ljubljana Jože Pučnik Airport: Use the scheduled airport–Bohinj/Bohinjska Bistrica bus when its timetable matches your flight: the quickest published trip is about 1 hr 15 min and roughly €7. If it does not run at a useful time, pre-book a GoOpti shared shuttle (often from about €14 when booked early) rather than taking an airport taxi; taxis are disproportionately expensive for this 65 km trip.
Bohinjska Bistrica railway station: This is the only rail station in the Bohinj area, on the scenic Bohinj Railway. It is useful from the Jesenice/Nova Gorica direction, but rail is not the efficient default from Ljubljana: use the intercity bus from Ljubljana instead of building an itinerary around infrequent train connections. The station is walkable to the compact town centre.
Ljubljana bus station: For most arrivals from Ljubljana, take the direct regional bus to Bohinjska Bistrica/Bohinj. Allow roughly 1 hr 25 min to Bohinjska Bistrica; services are frequent by Slovenian rural standards but not turn-up-and-go, so check the day’s timetable before committing to a connection.