Yes and no... there's certainly a big Celtic following here, as you'll see in the pubs and Dublin Airport any weekend, but the ManU/Liverpool/Leeds/Arsenal following is bigger. Not least because there's even more Premiership TV coverage here than there is in the UK, given that most people have access to both MOTD and RTE's Premiership highlights programmes, which are pretty much on a par with the BBC's, plus Sky Sports for the folk who want to pay for that.
All of which would be marginally less depressing if RTE didn't also show zero coverage of their own domestic league -- you still need Setanta if you want to watch that.