The correct phrase is "dream come true." However, the phrase "dream comes true" can be used in a sentence like this:
When you experience a dream that comes true, it means that an event or situation in your life has unfolded in a way that closely resembles or matches something you previously dreamt or imagined.
When someone refers to a "dream come true," they are describing a situation or experience in which something they have long desired or wished for has finally been realized or achieved.
