If you look a few posts above yours, you'll see that BA does not guarantee the Club Suites based on destinations except for New York flights which should all have it bar exceptional equipment change. For the rest, planes are not specifically assigned to a destination so whilst you can check the cabin on the flight you intend to take (just click on select seats and you'll see whether it is old or new layout) to see if it is currently planned as club suites, this can change any time for either better or worse.