The creed is the councils response to arianism. If you read the canons of the council communion is not in question, therfore it is not in the creed.
Code:
Let there be only four patriarchs in the whole world as there are four
writers of the Gospel, and four rivers, etc. And let there be a prince and
chief over them, the lord of the see of the Divine Peter at Rome, according
as the Apostles commanded. And after him the lord of the great Alexandria,
which is the see of Mark. And the third is the lord of Ephesus, which is
the see of John the Divine who speaks divine things. And the fourth and
last is my lord of Antioch, which is another see of Peter. And let all the
bishops be divided under the hands of these four patriarchs; and the
bishops of the little towns which are under the dominion of the great
cities let them be under the authority of these metropolitans. But let
every metropolitan of these great cities appoint the bishops of his
province, but let none of the bishops appoint him, for he is greater than
they. Therefore let every man know his own rank, and let him not usurp the
rank of another. And whosoever shall contradict this law which we have
established the Fathers of the Synod subject him to anathema.(2)
peace*