Lol! Anything at this point is guesses because your chick is so young and there are so many breeds whose chicks start out with the stripey chipmunk pattern. Your best bet as to what breed is to wait another 6 weeks or so, take new pictures and post them. Unfortunately bonus chicks from hatcheries are almost always roos.
LOL in my experience the bonus chick has always been a roo.... I have had a EEgger roo from them, a Golden Polish roo, an Orpington roo, a Motled Cochin roo..lol and this yr I expect a Buff Laced Polish roo as I ordered some Buff Polish hens from them.