there's plenty of 9/8 in Bach, and plenty of jigs, although they're called "gigues" -- IIRC the jig is originally an English dance form. Irish jigs are just one flavor of the form.
One place to hear Bach gigues would be the solo cello suites, the final movement of all six is a gigue. There are a few in the solo violin sonatas/partitas as well, but either marked only by tempo, or called "giga". They turn up elsewhere in Bach and the baroque, it's an old and well represented form throughout European music, not exclusively Irish.