The is some scientific debate, whether or not the size of an enviroment really impacts the over all size of the fish.
Also there has been studies that prove how nutrition and water quality effect a fishes growth rate.
Whether the size of a tank withing itself stunts a fishes growth can be debateable but if because the enviroment it was housed in caused adverse heath conditions because not enough volume to water to keep ammonia, nitrates etc down, then they could cause some growth issues.