art vs oenology

art and oenology both are nouns.

Word	Noun	Adjective	Verb	Adverb
art	Yes	No	No	No
oenology	Yes	No	No	No

As nouns, oenology is a hyponym of art; that is, oenology is a word with a more specific, narrower meaning than art:

art: a superior skill that you can learn by study and practice and observation
oenology: the art of wine making

art (noun)	oenology (noun)
the creation of beautiful or significant things	the art of wine making
the products of human creativity; works of art collectively
a superior skill that you can learn by study and practice and observation
photographs or other visual representations in a printed publication