wellness vs well-being

wellness and well-being both are nouns.

Word	Noun	Adjective	Verb	Adverb
wellness	Yes	No	No	No
well-being	Yes	No	No	No

As nouns, well-being is a hypernym of wellness; that is, well-being is a word with a broader meaning than wellness:

Other hypernyms of wellness include eudaemonia, eudaimonia, upbeat, welfare, wellbeing.

wellness (noun)	well-being (noun)
a healthy state of wellbeing free from disease	a contented state of being happy and healthy and prosperous