Depends on the repair kit, and the pond liner.

If it's a preformed plastic liner with just a hole you should be able
to use a pond repair kit as long as the patch is about twice as large
as the hole all the way around the hole. It should work fine as long
as it's safe for plants and fish.

If it's a sheet liner then you can use some of the scrap from the pond
to make a patch twice as large as the hole and use the same sealant you
used when you put the layers together.

All in all, yes patches work if they are for ponds. I know one guy
that tried a tire repair kit. It worked but it killed the fish. His
wife was so mad I thought he was going to move into the pond. hehe.

John Patrick,
www.birdoasis.com, where Window Birdfeeders are all the rage!