Any religious rite or act is impotent with respect to salvation. Faith and baptism are sometimes mentioned together in Scripture, but no one is saved by baptism itself. He that believeth and is baptized shall be saved. Some say that means baptism is a part of salvation. The issue is believing, which will manifest itself through a willingness to make a public confession.
Baptism is an intrinsic part of discipleship because it demonstrates genuine faith.
However, it is but a symbolic act of identifying with Christ. A disciple is someone who confesses Christ as Lord and Savior, believing that God has raised Him from the dead and declaring that belief publicly through baptism. A disciple is not a second-level Christian. One does not have to wait to become a disciple at some future time in his Christian life. Some say there are many Christians who aren't disciples.