Tires: Tire patch, dodge 4x4, winston brand

Question
Hello Mr.Sharp, I own a 1988 Dodge 4x4 half ton pickup that I use for work and off road leisure. My tires are Winston brand off road type.I have less than twenty thousand miles on these tires and they still have lots of tread left.
My question: My right rear tire had a bad leak after returning home.Not from the valve stem but from the tire tread area itself.I took it to the local auto repair tire center that I do business with. They charged me ten bucks and put a patch on the inside to fix it.
How reliable are these patches.
How long can I expect the tire to last and how safe is it to use for work and off roading with it patched.
Should I replace the tire.
Thanks! for answering. I appreciate it!

Answer
As long as the patch was applied properly, you shouldn't have any problem with it.  Patches are not a temporary fix, are meant to repair the problem for the life of the tire.  The only reason you should have to replace the tire is if the hole was in the sidewall.