LHR-BAH-DOH counts as one sector so 35TPs in discount WT, 70TP in full fare WT, 90 in WT+, 140 in CW and 210 in F.

What you can do if you want to spend another hundred pounds or so and really want the TPs is purchase a ticket LHR-BAH and then another BAH-DOH on the same flight.

When you get to BAH you can let the crew know that you are going on to DOH and then a chap will come on to give you your boarding card.

I would not try this with checked bags though...