We flew back on UA PPT-SFO on July 15th and we were allowed (actually welcomed) in to the lounge with our PP card. It was nice to have the AC and clean bathrooms (we did check in 3hours early). They only have cups of noodles, canapes, crackers, cornichons, olives etc for snacking on. There is a full spread of wine, beer, and other drinks. No showers (but we were prepared and showered off after snorkeling in Moorea earlier in the day before boarding the late afternoon ferry).
I don't know if there is a cut off for the PP card holders closer to the time of the flight or not. We were in economy, not business as a prior poster mentioned.