Bumble, it's interesting, isn't it? Although there are 4 Gospels, each one was written with a different purpose in mind.
Matthew was written to the Jews, and presents Jesus as King.
Mark was written to the Romans, and presents Jesus as a Servant.
Luke was written to the Greeks, and presents Jesus as Man.
But John was written to a universal audience and presents Jesus as God.
Therefore John focuses more on the miracles of Jesus rather than the other Gospels: the water into wine, feeding of the 5,000, walking on the sea, and raising the dead such as in the case of Lazarus.
The Bible states that all of the Disciples went to Bethany with Jesus but it does not mention that all were present at the raising of Lazarus. As a matter of fact it does not mention the Disciples at Lazarus's tomb. The reason John spoke of it was probably because he was there or he heard of the story and felt it was important to put in his writings.
If we look at all of the Gospels we see that each writer put down what he felt was important or was present for. The Gospels are like a puzzle, we must read them together to get the full picture of Jesus and His ministry. Just look at what was written above Jesus on the cross in all of the Gospels. In actuality it was written in 3 different languages but the 4 Gospels say that it says something different in each one. It doesn't mean they contradict one another, it just means that each Disciple could only read certain languages. Depending on the exact translation of the language it would be a little different.