I've been Elite for 10 years, Plat for 6 of those, and the only place I've had to show my card even though my boarding pass, PNR and JA show the correct name/status, is BOG at check-in. Counter agents have requested to see my card at least two distinct times that I can recall; I find this a bit discriminating/harassing and question their motive for their request but have never made a formal complaint.