How many bishops compiled the Bible?

Answer 1

There was no instant compilation. The Bible, as we know it, came about over a period of a few hundred years. The early Church had literature that it regarded as spiritually important. This included the letters written by Paul and others together with the canon of Hebrew scriptures that had previously been translated into Greek. To these were added the Gospels although these took many years to reach their present form. Various Church Councils ruled on what literature was acceptable and what was spurious. Following the First Council of Nicaea, someone had the bright idea of putting all of the accepted literature in book form (previously it was on scrolls) and this became known as "the books" or in Greek Biblia from which we get the English word Bible. However, the books of the Bible had been decided on at previous councils.

The councils involved many hundreds of bishops and there were a great many councils so the answer runs into thousands.