It is a clear historical fact that there was only one church in one city.
Ignatius of Antioch, a student of the Apostle John, and the third bishop of Antioch, while on his way to be martyred in Rome, wrote to
“the Church which is at Ephesus, in Asia,”
“the Church which is at Magnesia, near the Moeander,”
“the holy Church which is at Tralles, in Asia,”
“the Church...which also presides in the place of the report of the Romans”
“the Church …. which is at Philadelphia, in Asia,”
“the Church which is at Smyrna, in Asia,”
https://www.ewtn.com/library/PATRISTC/IGNATIUS.HTM
Regarding authority in the church he writes to the Ephesians (and to other churches, too)
CHAP. V.--THE PRAISE OF UNITY.
For if I in this brief space of time, have enjoyed such fellowship with your bishop--I mean not of a mere human, but of a spiritual nature--how much more do I reckon you happy who are so joined to him as the Church is to Jesus Christ, and as Jesus Christ is to the Father, that so all things may agree in unity! Let no man deceive himself: if any one be not within the altar, he is deprived of the bread of God. For if the prayer of one or two possesses[4] such power, how much more that of the bishop and the whole Church !He, therefore, that does not assemble with the Church, has even[5] by this manifested his pride, and condemned himself. For it is written, "God resisteth the proud."[9] Let us be careful, then, not to set ourselves in opposition to the bishop, in order that we may be subject to God.
CHAP. VI.--HAVE RESPECT TO THE BISHOP AS TO CHRIST HIMSELF.
Now the more any one sees the bishop keeping silence,[10] the more ought he to revere him. For we ought to receive every one whom the Master of the house sends to be over His household,[11] as we would do Him that sent him. It is manifest, therefore, that we should look upon the bishop even as we would upon the Lord Himself. And indeed Onesimus himself greatly commends your good order in God, that ye all live according to the truth, and that no sect has any dwelling-place among you. Nor, indeed, do ye hearken to any one rather than to Jesus Christ speaking in truth.
“The model of church organization that was formed during the first three centuries of Christianity was based on the principle of "one city-one bishop-one Church", which foresaw the assignment of a certain ecclesiastical territory to one concrete bishop. In accordance with this principle, the "Canons of the Apostles" and other canonical decrees of the ancient Church point to the inadmissibility of violating the boundaries of ecclesiastical territories by bishops or clergy.”
http://www.orthodoxytoday.org/articl...nOneBishop.php
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Dale Mody, The Word of Truth: A Summary of Christian Doctrine Based on Biblical Revelation, page 435
https://books.google.com.tw/books?id...page&q&f=false
or see the attached PDF file