Hello all,

I am planning a multi-city trip to Spain and am looking at the best flight options from a time/cost/avios/tier points perspective. I'm getting myself very confused in the process.

From looking at the avios earning section of the BAEC sticky, it seems that if any of my journey legs are operated by Vueling, there is no way of earning avios for that leg in a BAEC account. Is that correct?

One option is to book a flight on ba.com from LHR-BIO. It is IB flight number (operated by Vueling). The same flight is more expensive on ba.com than Iberia.com, which in turn is more expensive than Vueling. Is there any advantage to booking on ba.com? If booked in this way, can I access the BA lounge in LHR T3 with BAEC silver status?

I can't seem to combine this LHR-BIO flight in a multi-city on ba.com (even to go LHR-BIO/BCN-LHR) but I can book one-ways for these. This seems odd.

I can book the whole thing LHR-BIO / EAS-BCN-LON on Iberia.com as a multi-city. My guess is that from a BAEC perspective, if all of this is on Vueling metal, there is no advantage (unless I open an Iberia plus account, earn avios and transfer?). In this scenario, if the final leg was IB operated by BA, I would definitely earn avios through BAEC and have lounge access in BCN, correct?

I may end up booking a series of one ways or (gasp) be forced by others in my party to include some Easyjet flights if I can't work out an advantageous way.

I would be grateful for any advice the learned members of the BA board could give!