companion vs affiliate

companion and affiliate both are nouns.

Word	Noun	Adjective	Verb	Adverb
companion	Yes	No	Yes	No
affiliate	Yes	No	Yes	No

As verbs, affiliate is a hypernym of companion; that is, affiliate is a word with a broader meaning than companion:

Other hypernyms of companion include associate, assort, consort.

companion (noun)	affiliate (noun)
a friend who is frequently in the company of another	a subsidiary or subordinate organization that is affiliated with another organization
one paid to accompany or assist or live with another	a subordinate or subsidiary associate; a person who is affiliated with another or with an organization
a traveler who accompanies you

companion (verb)	affiliate (verb)
be a companion to somebody	join in an affiliation
	keep company with; hang out with