Haha, "phonics" in this context is when you represent the Irish pronunciation in English words and syllables, i.e., not very accurately.

"Phonemics" here is representing Irish the way many Irish scholars do in books and dictionaries such as Foclóir Scoile do, i.e., /b/ for broad b, and /b´/ for slender, etc. That is, specifically for Irish.

"Phonetics" is using IPA to represent far more detail, such as exactly what glide to use where, but using IPA often requires choosing a specific symbol where a range of sounds are permissible in the language.