Riesling vs Rhine wine

Riesling and Rhine wine both are nouns.

Word	Noun	Adjective	Verb	Adverb
Riesling	Yes	No	No	No
Rhine wine	Yes	No	No	No

As nouns, Rhine wine is a hypernym of Riesling; that is, Rhine wine is a word with a broader meaning than Riesling:

Riesling: fragrant dry or sweet white wine from the Rhine valley or a similar wine from California
Rhine wine: any of several white wines from the Rhine River valley in Germany (`hock' is British usage)

Other hypernyms of Riesling include hock, Rhenish.

Riesling (noun)	Rhine wine (noun)
fragrant dry or sweet white wine from the Rhine valley or a similar wine from California	any of several white wines from the Rhine River valley in Germany (`hock' is British usage)
white grape grown in Europe and California