The relationship doesn't have symmetry. BA - with BA codeshare - offers VY services earning TPs and Avios at a similar level to their own BA flights. But VY being a LCC this often means 5 TPs since low cost fares means the lowest buckets, but higher buckets are available and with it higher TP and Avios earning. Separately VY has its own Avios scheme which means even if you buy directly from VY on prime flight numbers you can earn Avios (but not TPs). You would have to transfer the Avios into your BA account and the process can be a bit shaky though I can normally get it to work. The VY Avios scheme is very similar to the Aer Lingus scheme, essentially a shell Avios system rather than the status system of BA and IB. IB, though, has a much more intensive relationship with VY than BA so you can quite practically get status and Avios as an Iberia frequent flyer on VY, a bit like those Loganair commuters who get Silver via LM but rarely fly BA.