The agent who told you your wife would have an SE chance of upgrading was wrong (big surprise). That was the case before this year, now the companion gets their own priority for upgrading, even if you're using your cert to do it (which would be the case if your wife were a Basic member, for example). One of the less logical moves by AC IMO, in a time of many illogical moves.
=aw
Aren't Basic members not able to use upgrade certificates in the first place, though status members are able to upgrade one companion? Or have I misinterpreted your post?