Supramolecular polymer systems consist of polymers with bonding groups that can form reversible inter-polymer linkages. In multi-component polymer systems, these reversible bonds play a key role in the self-assembly of these polymers into inhomogeneous phases. To understand the equilibrium phase behavior of these polymeric materials, we develop a field-theoretic model for a system in which an A and B homopolymer can reversibly bond to form a diblock copolymer. A free energy of bonding governs the strength of this reversible bond. Using self-consistent field theory, we find that the domain spacing of the lamellar phase increases drastically with increasing temperature. This results from the breaking of these reversible bonds at higher temperature and subsequent swelling of the lamellae with homopolymer. These results are consistent with recent experiments of Huh et. al. and suggest the great technological promise of using temperature to control the morphology and hence the material properties of supramolecular polymers.