Owen,

Avios can be earned on EI, Vueling (and via BA or IB any one world airline). Avis is the car hire partner and there are hotel partners too. You can earn at the Avios eStore, but a good start would would be an Avios earning credit card. Sounds like you have a U.K. address so the BA AMEX or AMEX Gold/Platinum would be good starts. (I’m happy to refer - both the referrer and referee get additional Avios/Amex MR points).

My AerClub resets in November - I think it’s a rolling calendar year. But remember that most fares only earn 7.5 tier credits, plus fares earn 15, but regularly fail to post. Luckily LHR is one of the best outstations for posting properly. Even so climbing the status ladder can be tiresome.

Avios availability to SFO can be tough, but you would also have BA and IB options. Connections from BHD (and other U.K. airports) are “free” for long-haul connections on BA.