no, the data files do mark all of the pressurized potions as multi-usable - but the one I tested really IS multiusable, it seems, whereas the other one is not.
That inconsistency is within KoL itself, and we could (should?) change our data files to agree with KoL - although I am tempted to report the inconsistency as a KoL bug report and see if they fix it there.
Edit: in particular, here is my inventory page:
pressurized potion of perception (7) [use] [use multiple]
pressurized potion of perspicacity (2) [use] [use multiple]
pressurized potion of pneumaticity (2) [use]
pressurized potion of proficiency (2) [use]
pressurized potion of puissance (2) [use] [use multiple]
pressurized potion of pulchritude (2) [use] [use multiple]