I would keep an eye on the Iberia Plus program to see if it follows BA's lead and goes to a revenue-based scheme for earning elite status. If it does not do so by March 31, then I would consider crediting your oneworld flights to Iberia Plus -- if you can find a good use for Avios.

Note that with Iberia Plus, you can often achieve status more quickly if you take connecting flights, rather than nonstops. For example, HKG-LHR-HKG roundtrip in Business would (currently) earn 1,000 Iberia Plus Elite Points. But HKG-DOH-LON-DOH-HKG would earn 2,000 Elite Points. You need just 2,250 Elite Points for oneworld Sapphire under the current Iberia Plus scheme.

With AA's AAdvantage program, you would need 75,000 Loyalty Points for oneworld Sapphire. Flights on CX, JL, MH, QR, and UL all earn Loyalty Points based on distance and fare class. But there are different redemption charts for each of those carriers. Business Class on JL and QR tend to earn more Loyalty Points than Business Class on CX, MH, and UL.