coming together vs gathering

coming together and gathering both are nouns.

Word	Noun	Adjective	Verb	Adverb
coming together	Yes	No	No	No
gathering	Yes	No	No	No

As nouns, gathering is a hypernym of coming together; that is, gathering is a word with a broader meaning than coming together:

Other hypernyms of coming together include assemblage, assembly.

coming together (noun)	gathering (noun)
the social act of assembling for some common purpose	the social act of assembling
the act of joining together as one	the act of gathering something
	sewing consisting of small folds or puckers made by pulling tight a thread in a line of stitching
	a group of persons together in one place