As far as I know, AA is the only OW airline to offer an excess baggage allowance to all OW elites on all flights (as well as priority tagging). OW doesn't have a published excess baggage allowance for elites, unlike the other two alliances, so it's up to the each carrier to set a policy. I'm not aware of any other OW carrier that has set its policy so generously. AA/BA/IB have a reciprocal baggage agreement due to their JV, but that's not for all OW elites.

If it's not clearly stated on other carriers' websites, I assume it's not a benefit. Now, I've had pretty good luck in getting carriers to look the other way when I check bags above my allowance, but I don't plan to expect it every time.