The irreversible growth of a binary mixture under far-from-equilibrium conditions is studied in three-dimensional confined geometries of size Lx×Ly×Lz, where Lz>>Lx = Ly is the growing direction. A competing situation where two opposite surfaces prefer different species of the mixture is analyzed. Because of this antisymmetric condition, an interface between the different species develops along the growing direction. Such interface undergoes a localization-delocalization transition that is the precursor of a wetting transition in the thermodynamic limit. Furthermore, the growing interface also undergoes a concave-convex transition in the growth mode. So, the system exhibits a multicritical wetting point.