Originally Posted by
oklAAhoma
That's not correct. EXPs can upgrade companions traveling on any published fare, and anyone traveling on a Y or B fare need not be traveling with an EXP to upgrade.
I *think* the OP is trying to differentiate between an upgrade that would require stickers and an upgrade that would not require stickers and using the term "companion" upgrade solely for the latter.
Regardless, it is confusing.