Premium economy upgradeable?
Sorry if this has been answered elsewhere, but can't find it.
I'm thinking of booking an (economy) oneworld explorer ticket, with the first leg LHR-CPT. If I take the optional paid upgrade to premium economy (BA WTP), what fare bucket does it book in to, and can that be upgraded with miles to Club World?
I also have some AA miles; I know the fare rules imply that you can't mix economy and business segments, but is there anything to stop me upgrading the AA legs with eVIPs or miles?
Many thanks in advance!