I would use editor templates and I would not use my NHibernate domain models in my views. I would define view models which are specifically tailored to the requirements of the given view (in this case limiting the amount to 2 decimals):
[DisplayFormat(DataFormatString = "{0:n2}", ApplyFormatInEditMode = true)]
public decimal Amount { get; set; }
and then:
@Html.EditorFor(m => m.Bank.Amount)