I looked at the back of Thomas Cook Summer Sun brochure and these are the Jet2 charters:
Belfast – Reus, Mahon
Edinburgh – Reus
Leeds Bradford – Faro, Malaga, Heraklion, Sharm El Sheikh, Tenerife
Manchester – Malaga, Ibiza,
Newcastle – Malaga, Rhodes
All bases. So i’m guessing there are no other bases.
However, Thomas Cook seem to be doing a lot of chartering with BMI.