The effect of perturbing the environment of a transition metal-ligand (M-L) complex by the addition of another metal atom, M’, was investigated by ab initio generalized valence bond/correlation-consistent configuration interaction methods. We have examined the properties of low-lying states of Pt-X, Zr-X, and (PtZr)-X, where X = {H, CH3}. The bonding trends of the transition metal diatomic-ligand complexes have been compared to their monometallic analogs. We find that Zr acts as an electron donor in all the diatomic complexes and that in these complexes the hydride-diatomic bond strengths are increased much more on average than the methyl-diatomic bonds relative to the monometallic complexes. For example, the PtZr-H bond strength is increased by over 14 kcal/mol relative to Zr-H, while the Zr-CH3 bond strength increases only by 4 kcal/mol in the bimetallic complex. The Pt-ligand bond strengths also both increase upon "alloying" the transition metal, but the magnitude of the changes are more similar-8 kcal/mol for the hydride versus 6 kcal/mol in the methyl complex. We comment on the implications of these results for the potential use of Pt Zr alloys as dehydrogenation catalysts.