To be honest, FB is hardly something that would attract a customer to UX over Iberia (for example, considering the core target market) so I'm not sure that they would come up with something worse for such purposes.

The very cheapest fares on UX never earned anything in Flying Blue (none of the few flights I have ever taken on UX earned anything in FB) so, if they at least give credit for every flight - perhaps by recognition of total spend, as I suspect may be the case - that would be a start