In my limited research of both, they have limited value. The airport lounge just provides access to lounges. You can sign up for free, but there is still a fee for each visit to a lounge. $27 per person. So a non benefit to me.
The companion certificate is much the same. I think it works on a zone setup, like the kind you get in junk mail. When you price them out you will find you can do just as well, if not better, just going out and buying two tickets directly from the airline.