Your PRSA is presumably with Bank of Ireland Life, a subsidiary life assurance company of Bank of Ireland. If the bank gets nationalised, it has no direct impact on the life assurance company, unless the government decided to sell off the subsidiaries.
However, if you are not getting tax relief on your contributions as you suggest, you should consider stopping your contributions as your benefits at retirement may be taxable, at least in part. Take professional advice before making a final decision.