They were illegimate and didn't enjoy the same rights as full blooded spaniards for sure. But the illegimate male children of spaniards had better mating privileges as nearly two thirds of mexican males have european Y chromosomes. That can't happen without the illegimate male offprings of spaniards having privileges that allowed them to mate at a much higher rate than native males since the full blooded spaniard population was never great enough to produce such drastic genetic disparity. What the privileges and rights were, who knows?