Legally, yes you should report it. (Would you get away with it if you forgot about it? Probably.)
In Turbotax on the Wages and Income page, go to the very bottom for "other uncommon income." One of the choices should be, I was paid additional wages by my employer that were not on my W-2 but should have been." You will end up paying 7.65% employee share of medicare and social security tax but not the 15% self-employed version of that tax.
