If I were you, I would more or less forget about "rebuke." It's a word that is really only seen in literature and sounds a bit old-fashioned.
If your boss said something negative to you, I would use the word "criticize" for that.
Criticize vs. scold is an important distinction, however. "Criticize" just means to point out a problem with something. It can be intended to be constructive ("constructive criticism") and it can be academic ("literary criticism"), where the intent is to find evaluate and interpret various ideas contained in literature. Criticism can also be rude, however. Consider a sentence like: "Why do you have to criticize everything I say?"
The word "scold" is used perhaps more often in the context of criticism directed to misbehaving children. For ex: "The mother scolded her children for making a mess on the floor."