Other than a carefully placed Easter egg, theres no reference to C.J. at all, this is because GTA V is in HD era while San Andreas was in the 3D era. According to @CaulynDarr the only character that has appeared in both GTA: SA and GTA V is Lazlow. He is in all the games.

Is CJ in other GTA?

While CJ works for mob boss Salvatore Leone, a GTA III character, during his time in Las Venturas. CJ also happened to work for his son Joey, another GTA III character, when the former was living in Liberty City.

What happen to CJ in GTA 5?

So where did CJ go in GTA 5? He went nowhere; he is still living in Los Santos according to the game along with Sweet and his homies. The only thing is that he probably doesnt live in the Grove Street anymore. But he is very much alive.