There is no moderator dedicated to Meta. So, reports made in Meta are handled by global moderators.
Global moderators:
mprep
hilariousandco
Mr. Big
Global moderators are allowed to handle reports globally on the forum and Meta is one of place they can handle reports. However it does not correct to say that all reports in Meta are only handled by global moderators. Admins (theymos, Cyrus) can handle reports and I guess staffs can do too.