Upvote:1
You can credit most TGV travels (to/from England, Belgium, Luxembourg, Germany, Switzerland) on the SNCF Voyageur traveler program, that's for sure, I read it in the conditions, each euro being worth 4 SNCF Voyageur points, plus one status point. It applies only if either departure or arrival is in France, though.
But I don't think there is any compatibility with other Railteam members (no occurence of the word Railteam in the conditions)