Nathanael means in the bible: God is generous. John 1:145-50 describes Philip’s friendship and his call to become a disciple. John 21:2 reveals that Philip was a Cana Galilee resident. Bartholomew is the most common name for him. This is because Nathanael, who is mentioned alongside Apostles as though he were of the apostolic rank and the Synoptists Matthew, is often cited. Mark 10:3 and Luke 6:14 refer to Bartholomew associating Philip with Nathanael. John, however, mentions Nathanael but never Bartholomew.
(in Bible Dictionary)