sparkleberry vs blueberry bush

sparkleberry and blueberry bush both are nouns.

Word	Noun	Adjective	Verb	Adverb
sparkleberry	Yes	No	No	No
blueberry bush	Yes	No	No	No

As nouns, blueberry bush is a hypernym of sparkleberry; that is, blueberry bush is a word with a broader meaning than sparkleberry:

sparkleberry: shrub or small tree of eastern United States having black inedible berries
blueberry bush: any of numerous shrubs of the genus Vaccinium bearing blueberries

Other hypernyms of sparkleberry include blueberry.

sparkleberry (noun)	blueberry bush (noun)
shrub or small tree of eastern United States having black inedible berries	any of numerous shrubs of the genus Vaccinium bearing blueberries