bench mark vs reference point

bench mark and reference point both are nouns.

Word	Noun	Adjective	Verb	Adverb
bench mark	Yes	No	No	No
reference point	Yes	No	No	No

As nouns, reference point is a hypernym of bench mark; that is, reference point is a word with a broader meaning than bench mark:

bench mark: a surveyor's mark on a permanent object of predetermined position and elevation used as a reference point
reference point: an indicator that orients you generally

Other hypernyms of bench mark include point of reference, reference.

bench mark (noun)	reference point (noun)
a surveyor's mark on a permanent object of predetermined position and elevation used as a reference point	an indicator that orients you generally