[DungeonMaster]

18 “Assuredly, I say to you, whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven. 19 “Again I say to you that if two of you agree on earth concerning anything that they ask, it will be done for them by My Father in heaven. 20 For where two or three are gathered together in My name, I am there in the midst of them.”

This is definitely not excluded to "bishops". It doesn't even make sense to try to parse this out as part applying to bishops only.

[D-fendr]

Would it be accurate to say, in your view, that there was a hierarchy in the Church when the Apostles lived, but not after they died?

[wmfights]

20 For where two or three are gathered together in My name, I am there in the midst of them.” This is definitely not excluded to "bishops".

I'm finding it useful in areas like this where there is such a strong disagreement on interpretation to look at what the Apostles actually did. If they believed the interpretation was meant to set up an autocratic hierarchal structure they would have personally picked the Bishops for churches they helped found and declared these Bishops the final authority. Instead, what the Apostles did was assist the various congregations in selecting their own leaders based on the charismatic gifts they possessed and the churches made decisions as a group, or through the elders (plural) that the congregation had selected.

[annalex]

This [Mt 18:18-20] is definitely not excluded to "bishops".

Verse 20 perhaps can be read expansively, but it has a qualifier "in my name", and who will decide that? The dispositive verse however is 17: it says that if an agreement is not reached, the Church decides, and since the collective of beleivers has already been dealt with in verse 16, the "church" in v. 17 is the hierarchical organization capable of making a uniform decision.