I think so, but a little emphasis on the think. I had booked a ticket using a BOGO companion fare as a placeholder (on suggestion of Alaska rep) while waiting for them to allow its use on Hawaiian flights from San Jose to Maui post merger. When I tried to change the dates and destination (as I was told I would be able to) I still had to call to get them to do it on Hawaiian, but I had to pay a fare difference, and when I asked if I could use the new Atmos card instead of the old card, she said no problem, as long as it was Atmos or Alaska branded. I do note that I still have both cards because the old one is, as you note, the one grandfathered in with no spend requirement for the BOGO. Hopefully you’ll be good.