To dream of a bucket with something in it represents efforts made in waking life to carry a situation forward. It may also reflect a burden you are carrying for something more important later on. What you have "put in" to relationship or situation to carry it forward. Doing something to carrying forward to the next phase.
Consider what is in the bucket for additional symbolism.
To dream of an empty bucket represents a lack of effort for something later on. You are not doing enough or haven't started your preparations yet. It may also be a sign that you are not doing enough to care about the future. Empty relationships with weakening future prospects.
Example: A man dreamed of someone telling him that a bucket was empty. In waking life he was required to fulfill certain obligations to prepare for a the next stage of a work cycle and failed to fulfill those obligations.
Example 2: A woman dreamed of an empty bucket being banged with a pole. In waking life she felt that her sex life was empty and had a sole purpose of keeping the marriage going.
Example 3: A woman dreamed of reaching for a bucket before falling into a well. In waking life she was pregnant and feared that going into child labor was going to be complicated. Reaching for the bucket may have reflected her feelings about the efforts of using her Lamaze class skills to help carry her through the labor.