I found it under article 9 of the RAO.there is nothing there that specifically states who the committee must be. I assume that in this case we default to the guidelines given to govern the other committees. It seems ti me that only ruling and teaching elders may serve.
It appears (as was mentioned on the floor of the Assembly) that Diane Langberg was on the Ad Interim Committee on Divorce and Remarriage. It does, however, note "advisor" next to her name, so she may not have been actually on the committee, particularly since there appear to be 7 others listed on the committee.
So it does seem a reasonable assumption that Ad Interim committees would be made up of REs and TEs. In the case of the recently approved study committee, it seems like having women advisors would be a good idea, but it sounds like they will actually be on the committee.