Welcome, Darren.

How often do you fly BA a year? The rewards for Bronze are minimal. It's not something I would go out of my way to do a TP run for. The easiest way to get 20 TPs would be a single Club Europe flight, which would earn you 40 TPs. Buy a Euro Traveller (economy) ticket one way, then buy a Club Europe (business) ticket one way, you can do that on the same booking.

If you do that, I would look at choosing Club Europe if it's an ex LGW/LHR flight, due to the lounge facilities being better. Spend a few hours in the lounge eating and drinking to get your money's worth.

Use flights.google.com to search for tickets. Fantastic Website to search for these things.