Grand Voyageur
You mean SNCF Grand Voyageur frequent traveller programme ?
Yes, I have been a member since the launch of the programme (1999 I think), as a former holder of their Euraffaires card.
You have to pay to join the programme, even though I have been offered my membership and renewal.
What to say ? Not a very exciting programme, but still worth enrolling if you use the SNCF network often ; it is a fair deal when redeeming your points for train tickets - otherwise : bof.
All the details are on their website.
Please post again if I may be of some help with any specific question.
F