oneworld Award Availability Tool?
 

I'm sure this has been asked before, but....does oneworld have anything similar to ANA's Star Alliance Tool for searching award availability across alliance flights for given city pairs?

No, an Expert Flyer search for select carriers' award space is not what I'm looking for. In one query, I want the tool to tell me which of many potential flights on multiple carriers has an award seat, in various classes of service.

Most people just use the BA and QF FF websites, though with mixed results. Have you tried registering for Awardnexus.com? It aggregates award availability from BA, QF, and JL in one location.