It is summarized in the first sentence of the Terms: U.S. Basic Platinum Card Members and Additional Platinum Card Members on the account and U.S. Basic Business Platinum Card Members and Additional Platinum Card Members on the account may bring up to two (2) guests per visit into locations of The Centurion Lounge in the U.S., at Hong Kong International Airport and at London Heathrow Airport for no per-visit guest fee (“Complimentary Guest Access”) through January 31, 2023.
Thank you - for some reason I thought there was an exception for spouses, minor children, etc.