Based on the figures you've given, the Bank of Ireland offer is around €115 per month lower, so you'd have recouped your expenses in a year or less, assuming the gap remains.
AIB don't do lender switches.
While it's possible that Bank of Ireland may hike up its variable rate, thus wiping out your savings before you've recouped your expenses, the Financial Regulator has taken a view on this recently. See
here. The ECB are not under economic pressure to put up rates in the short-term, although it will probably happen in due course. But when it does, any ECB rate hikes may well be passed on my both EBS and Bank of Ireland.