In the Space Quest I: The Sarien Encounter (original version) time sector Roger is certain that due to the case of time travel Bo's gender certainly changed to a female, and that "she' certainly remembered that he destroyed the BAR's slot machine. But there are other accounts that suggest that during his past (or pasts) that the bartender was a man.
Behind the scenesEdit
In Space Quest Companion, Roger calls him "Bo". Roger also doesn't appear to be sure of his/her gender. This applies to the VGA universe version of the game, not the original EGA however.
Bo appears to be a Superman reference. In Superman, Bo the Bartender (Bibbo Bibbowski) is a Metropolis bartender and a loyal supporter and friend of Superman.