Rule 240 of the Highway Code lists a series of places where motorists must not wait or park, including motorway hard shoulders and cycle lanes, but it does not mention bus stops.
Unfortunately, there are no easy methods for accurately predicting the fixed rate (currently 0%), so its hard to say whether you should buy now or wait until November in hopes that the fixed rate will increase.
But the owners did make a concession in their latest proposal by their willingness to wait 2 more seasons before imposing the hard cap as opposed to previous proposals where they wanted the hard cap to kick in right away.