Depends what you mean by 'companion pass'. It also slightly depends on which base you're at and which carrier you fly for.

Most of us have Delta buddy passes, United stopped giving buddy passes awhile ago but has a new companion program where you can throw one or two specific travelers on your benefits depending if you are married or not. And even though I'm the 'travel guy' I can't tell you off the top of my head if US Air, AA or Alaska has buddy passes available.

Perhaps someone who is based in SEA (AS), LAX (AA) or PHX (US Air) and is more familiar with those programs can chime in. Overall we do enjoy some pretty decent travel bennies.