Firstly, are you sure the pots are large enough? Fruiting trees need a lot of soil/feed, especially in a pot. Can you cut the bottoms out and let them root freely? Do you want to 'standard' the trees (think lollipop) or go for a more open look? Either way, you can create the shape and size you like anytime between now and February. Cut back to a flowering shoot. Fruiting spurs are already appearing on my apples from the current mild weather, but I will resist pruning until later, in case any frosts etc take the new spurs with them! A friend of mine prunes his fruit trees regardless of weather and they seem to be okay ...

i agree the trees have to be real happy to fruit etc . id be inclined to cut the bottems out your pots as most trees have realy long tap roots or plant them in the ground if you want fruit . it could just be age . id ask an expert like doctor bob on here or bamboo .