I take it Beso you are discounting Josephus because you think his mentions are forged or because he was out by 20 or 30 years?
There are an awful lot of famous people that are not mentioned in contemprary documents - we have a surprisingly small number of documents for Shakespeare for goodness sake!
I think the answer rather depends on whether or not you accept the traditional attributions of the Gospels and if the answer is "None they weren't written by the supposed authors" it's a rather peurile question.
So let's assume for the sake of argument they were.
Matthew or John were apostles - they certainly were meant to have witnessed Jesus' crucifixion and resurrection - I don't think that is meant to strictly speaking count as a miracle like walking on the water or the feeding of the 5,000.
My knowledge of the Bible isn't good enough though to answer the question - does anybody actually know if Mathew or John (who I think are the only supposed Gospel authors to meet Jesus) would have been present at any of the miracles?
It's interesting because if not the question of the reliability of the Gospel writers as witnesses can be called into question without first having to go down the rather tedious "Who really wrote the Gospels" road
Having a slightly closer look at this it seems that the claim is that John became an apostle after Jesus performs the miraculous draft of fishes so he'd have been an apostle at the time of the centurian's servant, the calming of the storm, and he and Mathew would have been disciples at the time of the feeding of the 5000 an the walking on the water
http://en.wikipedia.org/wiki/Ministry_of_Jesus
Don't know if there is any reference to whether either *were* there at the time though