Lounge access when traveling in Envoy/Business: OK to bring a guest?

I have two family members who are flying from Europe, and chances are good that at least one will get upgraded by using 30,000 miles and $300. If one person is upgraded and thus gets access to an Admirals Club departure lounge (and a US Airways Club lounge at a connection in the US), if a coach non-status passenger is traveling with upgraded person, can both access the lounges?

Thanks.