Allowing children to manage their pocket money on their own is a good thing. Children need to learn how to spend their money early on to make good habbits. I think it would help them later on in life if they learn at a young age how to manage the money.
Allowing children to deal with their own pocket money is an excellent way to teach them how to deal with larger sums of money when they reach adulthood. Letting them save for things they want, have regrets if they've overspent and can't afford other things they want, budget for how to acquire several things they want, and how to keep their money safe are all good things that cannot be learned too soon.
I believe that children should be allowed to manage their pocket money on their own. All children need guidance, and I am answering under the assumption that they've been taught general information about saving and spending. It's important that they get a chance to put this information into use and experience it firsthand. They will gain a greater sense of accomplishment and control by learning what to spend and what to save. The reward they will feel when they have successfully saved up for something they want will be a great learning experience that they can build on. If they don't try managing it for themselves, they'll not confidently know how to do it in the future with their larger, more critical sums of money.
Yes, it is wise to permit children to manage their own pocket money because doing so will help children learn how to be responsible with money, how to save up for something, and the negative feelings associated with unwise purchases. For children to grasp those concepts at such a young age, prior to having real-world responsibilities and consequences, that would be a valuable thing.
I believe it is wise to allow children to manage their own pocket money without help. I believe this teaches children the value of a dollar and it also teaches them responsibility. Learning about money is essential and I think it pays off if children learn about it slowly over time.