I understand why they would teach you that, but they are wrong.
Acts 15:6 Now the apostles and elders came together to consider this matter.
Decision making was done as a congregation. James the brother of Jesus presided over the meeting, but no one person made a final determination.
Acts 15:22 Then it pleased the apostles and elders, with the whole church, to send chosen men of their own company to Antioch,...
What you see is more of a Presbyterian or congregational structure.
Sorry, but the Jerusalem council doesn't count as the regular mode of operation. That was what would be classified today as an "ecumenical synod" (same as Vatican II). In the exercise of the day-to-day administration, the heirarchial model was "it".
And deciding who to send on a "site visit" is NOT the same thing as deciding who will be a priest or bishop--which again was done according to the heirarchial structure.
Y'see, as I said, I just got through studying ALL of Acts, and the standard Protestant practice of selective quotation isn't going to cut it.