FRance-yes, but do not expect too much of it-Condition: ALSO a RES for a TGV in the next 1-2 hrs must be held (but that applies to everyone)
DE=Germany definitely NOT-is also clearly mentioned on entry. Unless you are also in the DB-BahnBOnus program with enough status. It is since shortly all modeled like airlines do.
GB has the best ones, but often quite busy, AT the most welcoming and well -assorted (though this all dates from pre-covid).
IN GB on IC-trains of some companies you are also treated to free food/snacks+drinks
CZ/CD apparently has 1 lounge in Praha/HN, but this may have been sourced out.
Note: I just read that those of OeBB are ALSO open to anyone with a real SLEEPerticket-even if that is in 2nd. Also after arrival next morning.