offering vs subject matter

offering and subject matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
offering	Yes	No	No	No
subject matter	Yes	No	No	No

As nouns, subject matter is a hypernym of offering; that is, subject matter is a word with a broader meaning than offering:

Other hypernyms of offering include content, message, substance.

offering (noun)	subject matter (noun)
the act of contributing to the funds of a church or charity	content communicating a message; what something is about
something offered (as a proposal or bid)
the verbal act of offering
money contributed to a religious organization; item or items contributed to a religious organization for religious purposes