The teaching of both Roman and Eastern traditions is that the Bible can only be understood in the context of culture and traditions which birthed it.
The reader must take into account the conditions of their time and culture, the literary genres in use at that time, and the modes of feeling, speaking and narrating then current. "For the fact is that truth is differently presented and expressed in the various types of historical writing, in prophetical and poetical texts, and in other forms of literary expression. (CCC 110)
Understanding Paul but ignoring those who knew him (like Ignatius, Polycarp, or the contents of the Didache) would be like studying Luther but claiming anyone who knew him was a quack. All of those documents testify to a church with a defined set of bishops, given the authority to rule over and teach the Church (strikingly similar to the Episcopai Paul talks about in the New Testament).
The Church claims itself to be "the pillar and foundation of truth" (CCC 171 citing 1 Tim. 3:15). The Roman Catholic Church cites 1 Timothy as an example for people who view the Bible as authoritative (note: the Bible does NOT claim that title), but the Church would be the pillar and foundation even if Paul had never said that. In fact, there is a very, very long list authors, going back to the very beginning of Christianity who testify to the Church.
All of that said, you can still find testimony of the authority of the Church and the validity of her practices in scripture, but that is a different from saying "we interpret the Bible to endorse us therefore it endorses us".
As a counter argument, you might reply: The Bible speaks of deacons, presbyters, and episcopai. These were men selected and ordained by the Apostles for the purposes of administration and evangelization. These early authors claim to be or to know deacons, presbyters, and episcopai. They claim to have served under the Apostles. (we'll ignore the fact that presbyter came into English as "priest", and episcopai came into English as "bishop"). Their instruction and testimony is a valid source of instruction in matters of faith.