We'll be leaving Switzerland by going Montreux to Lyon, France. I think we'll get a pass of some kind for Switzerland - probably the half fare card. So will a pass cover the whole trip to Lyon, or just the Swiss part?
If it only covers the Swiss part, do I need to book the French part in advance to get cheap fares, but leave the Swiss part to buy on the day with the pass? This could mean that if the train Montreux to the border ( Geneva?) is booked out, we don't make the connection.