These two concepts are not directly related in numerology. "Dream of the underworld" is a supernatural phenomenon, which is often related to souls, undead, ghosts and so on. "Phoenix reincarnation" is a kind of myth and legend, which is often related to the legendary phoenix and reincarnation.
Numerology mainly focuses on birthdates's five elements, which is used to calculate personal destiny and personality characteristics, and has little to do with supernatural phenomena and myths and legends.
So as far as I know, there is no direct connection between the dream of the underworld and the reincarnation of the phoenix, so it can be said that the dream of the underworld does not necessarily conform to the meaning of the reincarnation of the phoenix. But the dream of the underworld is indeed a mysterious phenomenon, which needs further research and exploration.