I'm sorry you are in this position. With new liner, one would expect the pool would retain water..."from day one."
The answer on the patch is that it is VERY dependent on the skill and materials used by the installer, on the duration of the patch, nobody can give you a definitive answer. Is he willing to warranty the patch for the life of the liner in writing as he represented? What is the definition of "life of the liner?"
Unfortunately, you are in a very *&$@ position.
In the contract for the replacement of the liner, what was the representation of the warranty? If there was a hole from "day one" would seem to me their responsibility. Did you confirm the hole before they left? Why did they deny a warranty claim?