tall bilberry vs blueberry bush

tall bilberry and blueberry bush both are nouns.

Word	Noun	Adjective	Verb	Adverb
tall bilberry	Yes	No	No	No
blueberry bush	Yes	No	No	No

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

tall bilberry: high-growing deciduous shrub of eastern North America bearing edible blueish to blackish berries with a distinct bloom; source of most cultivated blueberries
blueberry bush: any of numerous shrubs of the genus Vaccinium bearing blueberries

Other hypernyms of tall bilberry include blueberry.

tall bilberry (noun)	blueberry bush (noun)
high-growing deciduous shrub of eastern North America bearing edible blueish to blackish berries with a distinct bloom; source of most cultivated blueberries	any of numerous shrubs of the genus Vaccinium bearing blueberries