Looks like anybody in C or F has
access.
Our Arrivals Lounge in San Francisco, located in Terminal 3 on the baggage level, is a retreat where United Global First and United BusinessFirst customers arriving by noon on a same-day ticket may freshen up with a shower. Guests can enjoy a breakfast and use complimentary Wi-Fi.
Originally Posted by
wxguy
GS on any ticket, (Y, C, or F -- revenue or award), arriving from an international destination can access the Arrivals Lounge. 1Ks can access arriving on any C or F international ticket (including upgrades and awards). Guests are never permitted.