Let's assume as you are doing that the dormitory is not at peace now :)
You must choose between "bring about peace in the dormitory" or "bring peace to the dormitory". They cannot be combined as you are doing because the prepositions about and to express opposite spatial/locative ideas. These locative meanings are present even though the collocations have acquired an abstract meaning.
bring about peace is a variant of bring peace about. The meaning doesn't change when the position of about changes.
If you intervene in a fight (that is, if you come between the fighters), you can bring about peace. You effect change in the midst of contention.
Just as you can spread rumors about, you can bring peace about. Compare the collocation "around and about".
If you bring peace to a place, there is no sense that peace is effected in the midst of the contention, as there is with "bring about peace" or "bring peace about". The preposition to at its very core expresses the idea of 'in the direction of a destination, towards'.
So you bring about peace in a place, or bring peace to a place.