bulletin vs news report

bulletin and news report both are nouns.

Word	Noun	Adjective	Verb	Adverb
bulletin	Yes	No	Yes	No
news report	Yes	No	No	No

As nouns, news report is a hypernym of bulletin; that is, news report is a word with a broader meaning than bulletin:

bulletin: a brief report (especially an official statement issued for immediate publication or broadcast)
news report: a short account of the news

Other hypernyms of bulletin include account, report, story, write up.

bulletin (noun)	news report (noun)
a brief report (especially an official statement issued for immediate publication or broadcast)	a short account of the news

bulletin (verb)	news report (verb)
make public by bulletin