No, they are independent of each other. There are Provisional and Full licences in both catagories.
For motorcycles:
Provisional drivers are restricted to 125cc or lower and must show "L" plates (Learner). There is a 2 part practical test - Part 1 is off-road and is concerned with bike control around a set course. Part 2 is on road pursuit type by an examiner. You are given a route to follow and the examiner follows on a bike. I believe they use an intercom system now for giving instructions. This includes emergency stopping. I don't know if riders now have a theory test as well but I suspect they do. If you don't pass it within 2 years you are automatically banned for a year.
Full licences are now restricted to lower capacity machines for 2 years after qualifying I believe. When I took mine there was no such restriction... the restriction on bike size for a learner then was also 250cc.
Car licences are provisional or full. Learner drivers must be accompanied by an experienced driver with a full licence over 21 and show "L" plates. Two part test - you must pass the theory before proceeding to the practical road test. Full licence allows you to drive up to 7500kg van(light goods) with a trailer, or a minibus (up to 16 passengers) with a trailer, or at least mine does. PSV (passenger service) and HGV (heavy goods 1 - 3) are seperate licences which you can take after you get your basic full licence.
Catagory B1 - motor tricycles up to 550kg unladen - a reliant robin is classed as a motor tricycle.
My licence has catagories:
A (any motorcycle with or without sidecar),B1, B (car) C1 (light goods), D1 (minibus), BE (car+trailer), C1E (light goods+trailer) and D1E (minibus+trailer). There are laso some gatagories for tractors, road rollers etc - FKLN and P, plus G and H. Most of which I'm unlikely to use.
There are 2 catagories under A - </= 25kw or </= 0.16kw/kg and unrestricted. There are also age restrictions on some of the vehical types, but they don't apply as I'm over 21.
When you reach 70 you have to re-apply to keep your licence at present, but there has been a lot of discussion about people having to take regular updates to keep their licence.