white tie vs bowtie

white tie and bowtie both are nouns.

Word	Noun	Adjective	Verb	Adverb
white tie	Yes	No	No	No
bowtie	Yes	No	No	No

As nouns, bowtie is a hypernym of white tie; that is, bowtie is a word with a broader meaning than white tie:

Other hypernyms of white tie include bow-tie, bow tie.

white tie (noun)	bowtie (noun)
bow tie worn as part of a man's formal evening dress	a man's tie that ties in a bow
formalwear consisting of full evening dress for men