The in-game Wonderboy artwork in Little Haiti is a parody of the real life game of the same name, from 1986, the same year GTA Vice City is set in. Wonderboy was published by Sega and developed by Escape.
The reference is another dig at platform games from the 80's. Thus, the in-game Wonderboy, being bald, is likely a vandalized version of the original Wonderboy, who earned recognition for his alluring hair.
GTA San Andreas
Wonderboy can also be found on the same road as the Zombotech Corporation in Doherty, San Fierro in GTA San Andreas. He is seen on the graffiti-ed windows of a store next to the Stiphes Mortuary.