A pocket is very similar to a handbag or similar items. All these items keep our important valuables safe, protected and organized, and conveniently available. See the meaning of a “handbag” or a “purse” and the meanings of the items that you usually find in them. This will give you an idea of the meaning of pockets. Although, the value of items in pockets is usually not as high as those in purses or handbags. I assume you are referring to the pockets of clothes. Clothes are all about our spiritual preparation for ministry or about our preparation for life. So obviously, the pockets of clothes are all about spiritual valuables (things that are important to us) that we want to take with us when we go out to minister to people.
Whatever items we find in pockets (symbols) will shed more light on the meaning of the dream or vision.