I don't know, with Commodore being an American company, I'd think the C64 surely was big enough there as well.
But that's actually not even the point here, because Bomb Jack originally is an arcade game (so what platform that longplay was recorded from doesn't really matter) an Jet Pac was best known on the Spectrum - which I'm fairly sure was a machine that didn't matter much outside the UK in its days and definitely less than the C64. So if we go with John being American asn an explanation, it would be actually even more puzzling in a way that he's comparing the mini-game in Touryst to Jet Pac instead of Bomb Jack.
I'm aware this is rather pedantic, but it just bugs me somewhat especially as he's not the only person to do so, I've seen that comparison a number of times by now.