Went to the EWR clubhouse last month on an Alaska boarding pass, quoting myself from the alaska thread, got in around 430pm est or so:
Reporting from VS lounge in EWR B2 satellite - it's crowded as hell and was barely able to find a seat, but they do have the scan to order which is nice. Amex Plat gives access, which is much better than the old A gates that had no lounge. No real TSA Pre line though. EWR-SFO flies out of B57. No way to enter any other terminal or satellite w/o going through security again.
It was fairly small. I remember being very impressed with the plating when they served me the food, but they also forgot to serve me the alcoholic drink I ordered. All the other ten or so flights departing from that satellite were international. There is also a BA lounge too I think I could have accessed instead.