Thanks Travelwell for these tips.
It clears up a mystery for me – I recently flew London to the Gulf, then between two gulf cities, then back to London, all 3 legs on BA Club World. Slightly surprised to be 360 tier points better off, with even the short (less than1 hour) leg in the Gulf counting as Intercontinental. But your post suggests this is how the BA system works.
Can you confirm this is correct?