So BA has updated its website on the new BAC, but someone should have proof-read it. It says Tier Points are awarded on "every eligible flight with British Airways and our oneworld® partners" and then at the bottom of the page says.

"Eligible flights

Eligible flights are defined as those flights marketed by British Airways.

'Marketed' means the flight will have a BA flight number (in your itinerary or on your ticket). The aircraft you travel on can be either a British Airways aircraft or belong to one of our franchises or air partners.

Flights marketed by other airlines, reward bookings and agency or industry-discounted bookings aren't eligible."

https://www.britishairways.com/conte...ut-tier-points