Originally Posted by
fifty_two
talking about skyteam only , while there are exceptions like DL or AM that you need to be aware of but its case per case , you should be allowed a free luggage as a skyteam elite or elite plus when flying skyteam marketed and operated flights (AFKL partners like CM are another story , its out of scope)
AFAIK, the only checked bag exception (now that AM apparently gives STE a checked bag on basic) is DL flights to EYW where the particular situation (aircraft and runway characteristics) limits all passengers to 1 checked bag regardless of ticket or status... STE in basic gets 1 free bag, same as any status in J. Otherwise it's alliance-wide that if you're flying an airline different from the airline you have status with, STE get a bag.