Using a numerically exact approach to the dynamics of a molecule-photon field-coupled system, we investigate the quantum-phase and the information-entropy dynamics of molecular dimers interacting with a single-mode coherent photon field. The intermolecular interaction between monomers is treated by the dipole-dipole interaction. The influence of the dipole-dipole interaction on the feature of the collapse-revival behavior of dimer population is revealed from the viewpoint of the photon-phase dynamics and the entanglement between dimer and photon.