Is the 'Isha' prayer valid, and are the prayers in which "Rabbana wa lakal-hamd (Our Lord, and to You be all praise)" was said after standing from bowing valid?

The worshiper says, "Our Lord, and to You be the praise" while rising from bowing, not after standing upright. What you did out of ignorance, not intentionally, by offering the praise after standing upright, means all your prayers are valid, and you do not have to repeat them.