Well it would depend what percentage jungle the parent animal was to begin with. If the father lets say is 50% jungle and 50% coastal and you paired that to a pure jungle the resulting offspring would be 75% jungle 25% coastal. if you pair the offspring with another pure jungle you will get 87.5% jungle 12.5% coastal. Basically the more you breed them to pure jungles the more watered down any coastal genes they have become.
You seem a bit confused here on the whole jungle/coastal thing. Jungle and coastal are simply subspecies of carpet python. They're not morphs. So if you breed any jungle/coastal mix regardless of whether they are jaguar or not to a pure jungle you don't get some jungles and some coastals. You just get offspring with less coastal blood in them.