After holding your licence for 2 years, you can then take another practical test to get an unrestricted A Motorcycle licence. This licence will allow you to ride a scooter or motorcycle of any power and size, as long as you are 21 or over.
There are two ways to obtain your A Licence:
If you have held your A2 motorcycle Licence for two years, you are then eligible to take another practical test
If you're over 24 and haven't held an A2 Licence for over two years, you have the option to take the Direct Access route which can be done by completing your CBT, Theory tests and a practical test.
This will then ensure that you are allowed to ride any motorcycle or scooter without L plates, whilst carrying a passenger.