International upgrades from Main to C+
I am booking a trip to EDI from SEA, looking at various connecting options. All of them have C+ class of service. I'm a Plat. Do I understand correctly that I get upgraded from Main to C+ on any flight that has a C+ class of service? I know that's what the Delta site says but I have a nagging recollection that such upgrades were only for domestic legs at one time. And the same would be true for my companion on the same PNR? Thanks.