Rememer this flight is on AC metal so you can only upgrade on the day of travel. Based on the rules, you should be able to upgrade your companion.

Last year when I was travelling with my dad and brother, I got upgrades for myself and one of them at 100 hrs and then the other at the airport and he was placed on the standby list as a EP even though they are both only CLUB. I technically upgraded 2 companion with me.

After all, it all depends on the agent at the gate.