I'm late to the party, but for clarity's sake: NRSA/NRPS may use the United Club on Intl J passes, and I believe Star Alliance lounges as well (both only once cleared into the seat if standby)
There's a page on the intranet explicitly disallowing NRSA/NRPS from the Polaris Lounge. I'm happy to refer people with access how to find it, privately.
Please don't get yourself or your sponsor in trouble.