Is This Normal For My atiels And Water?

Yes this is normal bathing behavior. I would recommend providing your tiels a separate shallow dish for bathing rather than them bathing in their water bowl. If I remember correctly your tiels have been mating so it is good that they have begun bathing as the female will often bath when she is off the nest to help keep proper humidity for the eggs. So make sure you provide water appropriate for bathing when she is sitting her eggs.