I am iranian , are my family need have physical examenation record for z-visa?

if my wife and children names have been mentioned in invition letter for z-visa which has been issued for me, then they can apply for z-visa same time of me?
Or if authorized unit from China issue invitation letter for z-visa for my wife same as me them she can apply for z-visa in iran? is it necessary my wife enter with z-visa same as me or not?