We present a detailed study of the structure and properties of a supramolecular complex formed via hydrogen bond association between poly(acrylic acid) chains and an imidazole-terminated biphenyl mesogen. The system exhibits a rich phase behavior as a function of temperature and stoichiometry, expressed as the molar ratio S between the number of mesogens and binding sites present. Smectic mesophases are formed for all S >= 0.033, a surprisingly small number. The dependence of the characteristic length scale of the mesophase on stoichiometry does not follow the expected 1-D swelling law. At low stoichiometries, S <= 0.2, the system exhibits little or no change in structure up to temperatures as high as 200 degrees C, beyond which changes become temperature irreversible. In contrast, at higher S, the system features complex thermally driven transitions among tilted monolayer and bilayer arrangements and complete, reversible isotropization of the system at elevated temperatures. Over a limited range of temperatures and compositions, a supramolecular length scale emerges that is well beyond the upper limit imposed by a bilayer construct and thus cannot be accounted for within the conventional paradigm. Binding isotherms reveal that the polymer has a limited capacity for the ligand with saturation occurring for S >= 0.33. These results suggest that the common assumption of homogeneously distributed tightly bound ligands with layer-like phase separation from the polymer backbone do not apply in this system over all compositions. The anomalous phase display is consistent with demixing between polymer rich and polymer poor domains due to the presence of excess unassociated mesogen, which can act as a solvent for the system.