No your car license counts as a provisional bike license
If you have got a ECU restriction kit (rather than faffing with washers, etc) then you can ride to the test centre with the full power ECU in your pocket and just switch it round when you get there. Or you can just do your test on a restricted bike, as mazda 6 says, cos they'll never know
Personally I think the whole 33bhp thing is stupid. You learn, and take a test, on a 125... then you've got permission to ride anything with 33bhp? Riding a 125 is so much different to a proper bike regardless of it being 33bhp restricted or otherwise. If you want to ride a big bike, learn to ride big bikes (or they should make it so that a 33bhp license is trained for and taken on a 33bhp bike - but I suppose that'd be too much hassle

however building the new test centres at £6m a piece wasn't too much hassle at all

)! Two of my mates have gone the restricted route and they had such a shock from 125 to big bikes that one binned his bike and has since given up, and the other
went back to a training school for lessons on big bikes! The crazy thing is that training schools recommend the 33bhp route as "the safest way" - poppycock! £0.02.