Hello ​@ginga 

Yes, an “autocar” or a “car” is a bus in France, AURA means the region Auvergne - Rhône - Alpes.

It is strange, no tickets are currently available for these buses, for example for today. I think that tickets may be only available on the vending machines TER AURA in Lyon Part-Dieu or at the ticket office.

If the bus is in the timetable when you travel, it is feasible, but I cannot say if your pass will be valid or not. The indication “Mandatory reservation” in the Rail Planner is also surprising.

SNCF haven't published all timetables yet for travel after 31 March, so I looked at Wednesday 26 March. I see several direct buses on the regional TER website listed as "Car TER”, which means it's a bus operated by or on behalf of SNCF and passes are valid. Reservations are not possible and if the app claims they're mandatory, then that's either an error in the app or in the timetable data delivered by SNCF.

Thanks for the replies.

My preference is the train TER 17978 which also isn’t ‘bookable at this time.

I’m correct in assuming that the Eurail pass is accepted by SNCF for trains & buses?

Really appreciate the replies.

With few exceptions that don't apply here, reservations for TERs can't be booked. You add the train to your pass, board and find a seat.

Correct, but passes are not valid in Ouigo (SNCF low-cost brand) and RER (suburban trains around Paris).

Thanks rvdborgt

You’ve helped me avoid mistakes I would have been certain to make