I was just searching and found
this on Wolfgang's Vault of 3 Great Society live tracks from the Fillmore on 10th June 1966 but when I compared it it's quite clearly the same recordings as on Collector's Item - which is supposed to be recorded at the Matrix - but it's quite possible that some of it might have been recorded at the Fillmore too.
I also found a copy of an old magazine Cream Puff War
here that has a long interview with The Great Society as well as some interesting information about recording dates. It also says that a 16-song recording exists from the Matrix "circa April'66" (they actually played the Matrix 15-19th March), and comparing the song titles, the 7 songs from San Franciscan Nights are from that recording. I wish we could hear the whole thing!
["Long Lost Lover" is the wrong title, it's actually called "Black Crow Blues" and it's a Bob Dylan cover. Also I think "Sure Lovin' Man", listed in that magazine as "Slow Movin' Man" should be called "Slow Lovin' Man".]