Literally they’re “man spouse” and “woman spouse”. (Céile has more than one meaning.)
Well one of their definitions for céile was "with each other" so it makes sense that céile dancing would be "dancing with each other"
do not quote me because I still dont know much but I think bean isnt bhean because its not preceded by an. Anyone correct me if wrong.
I think you're right. And even though the feminine noun 'bean' is not lenited in the absence of 'an', the word 'bean', being feminine, will lenite any adjective that follows it even when the word 'bean' itself is not lenited.
It seems, though, that 'céile' is not an adjective. The dictionaries at teanglann.ie only list it as a noun. But from the rules there [http://www.nualeargais.ie/gnag/lenition.htm#nouns], lenition can also apply to nouns that follow a feminine noun… rule 4 ? Maybe 'céile' is the genitive here, because for this word it's the same as the nominative (4th declension).