Yep, they all were! You say "no", I say "Yes".
Because the Bible is silent on that particular matter, and, because
Mark 16 links Baptism to salvation, then I have to say "YES".
Furthermore, all the Apostle, excluding Judas, were there in
Acts 2 when Pete preached and supported him in his preaching of
Acts 2:38.
The preponderance of evidence will support the saying of "YES" to the question asked.
Jesus was baptized under John's ministry so it goes to say that he was baptized unto John's baptism. Jesus was not baptized for remission of sins but was beng Baptized for:
1- Example
2- The washing into the office of the Priest