I think mine has the Ozone jet, as there is a very small pointless jet in the foot well.
It does blow water out, but as it's so small (about 10mm exit), i don't see its function.
I think the polythene tube is probably for the Ozone generator, and more than likely connected to the jet in the footwell, as it goes off in that general direction.
However, I have no Ozone generator fitted to the tub.
The connections are there for one though.