mellowness vs bonhomie

mellowness and bonhomie both are nouns.

Word	Noun	Adjective	Verb	Adverb
mellowness	Yes	No	No	No
bonhomie	Yes	No	No	No

As nouns, bonhomie is a hypernym of mellowness; that is, bonhomie is a word with a broader meaning than mellowness:

Other hypernyms of mellowness include affability, affableness, amiability, amiableness, geniality.

mellowness (noun)	bonhomie (noun)
the property of a sensation that is rich and pleasing	a disposition to be friendly and approachable (easy to talk to)
a soft shade of a color
geniality, as through the effects of alcohol or marijuana
a taste (especially of fruit) that is ripe and of full flavor
a feeling of good humor and sympathy through maturity or intoxication or a relaxed state