Is a person rewarded for doing good in his dream?

We do not know how a sleeping person can do good in their dream, unless what is meant is the remembrance of Allah or recitation that issues from some sleepers unintentionally and without awareness. Intention is the basis of reward and punishment. There is no reward or punishment except with intention, and the Prophet, peace and blessings be upon him, said: "Actions are but by intentions." What issues from a sleeping person unintentionally carries no reward and no sin, for "The pen has been lifted from three: from the sleeper until he awakens."