I believe that the water into wine story is a parable. The wedding guests accuse the host of serving an older vintage first and then bringing in a newer vintage. The opposite of what was the practice at parties. The old vintage, the separation from God by Jews and man and the new vintage, the Covenant that Jesus brought.
Using that same logic, though, even Jesus' death on the cross could be considered just a parable, as the act is loaded with theological meanings.