Not sure, both supplied by the same wholesaler. Think Rhinegold may be made with european leather whilst the Heritage is english leather? I have a Rhinegold bridle which is fine and had a heritage comfort one which was good quality for the price.
I think the only difference between them is that Heritage is english leather and rhinegold is european leather.
I have a Rhinegold one which is almost 5 years old now and still in really good condition, used for everyday and competing. I wouldn't hesitate to buy another.