bergamot orange vs orange tree

bergamot orange and orange tree both are nouns.

Word	Noun	Adjective	Verb	Adverb
bergamot orange	Yes	No	No	No
orange tree	Yes	No	No	No

As nouns, orange tree is a hypernym of bergamot orange; that is, orange tree is a word with a broader meaning than bergamot orange:

bergamot orange: small tree with pear-shaped fruit whose oil is used in perfumery; Italy
orange tree: any citrus tree bearing oranges

Other hypernyms of bergamot orange include orange.

bergamot orange (noun)	orange tree (noun)
small tree with pear-shaped fruit whose oil is used in perfumery; Italy	any citrus tree bearing oranges