Thanks for the replies guys. I'm gold preferred on US... so sapphire on OneWorld. I checked in with BA yesterday and didn't have a problem getting a second bag free... which has, so far, been my experience traveling internationally as a sapphire OW member on Iberia, BA and US. But maybe two free bags is the standard for those airlines when traveling international.

I've always found that a bit strange that OW offers no extra baggage for sapphire members. When you look at *a the equivalent status (*a gold) gets you an extra bag. You would think OW would try and match that to stay competitive with *a. Even more strange is that I've never had an issue checking a second bag for free with OW airlines. It seems they're not very strict with this rule.