As Englishal points out, your rating (issued by the CAA) is for Single Engine Landplanes. Provided that you've done three landings and takeoffs in the last 90 days you are "current" and able to carry passengers.
The differences training you're doing on the TB20 for VP prop and retractable undercarriage is simply that, differences training which must be signed off in your logbook - nothing more.
Whether your club will want you to take a check ride in a Warrior after a 3 month lay off from flying them is another question. You may also wish to consider whether it would be sensible to do so, before committing yourself to flight with a friend aboard.
Pronto