Yes, JOHNNIES is a Scrabble word!

Letter values in Scrabble US: J 8, O 1, H 4, N 1, N 1, I 1, E 1, S 1.

Is it a valid word?

JOHNNIES is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

`Johnny' was applied as a nickname for Confederate soldiers by the Federal soldiers in the American Civil War; `greyback' derived from their grey Confederate uniforms

Also: johnny reb.

Not playable in Scrabble US: GREYBACK.