Hahaha, fair.

Though, according to Statutory Instrument 113/1993, the Irish and English markings can be used on their own, or in conjunction with each other:

www.irishstatutebook.ie/1993/en/si/0113.html

The problem is that Gaeilge (Gaelic) is the national language and it would simply cost twice the amount to paint Bus Lane underneath Lána Bus and the Irish government is cheap af just like most governments.