If you want to bind only the Contact, but this is not the Model of your presentation, but it is part of it, as you wrote, you can do the following to create:
[HttpPost]
public ActionResult Create([Bind(Prefix = "Contact")]Contact contact)
, UpdateModel , :
[HttpPost]
public ActionResult Edit([Bind(Prefix = "Contact")]Contact contact){
UpdateModel(contact, "Contact");
}