The spectrum of bound states of He atoms adsorbed on Ag(110) is calculated, using an interaction potential based on effective medium theory EMT for the repulsive term A exp(-bz) and the Zaremba-Kohn form for the attractive van der Waals dispersion term. The electronic charge density of the host in the selvedge region is modeled by superimposing atomic-charge densities using the Herman-Skillman tables and the prefactor A of the repulsive term is fitted to the exact ground state energy obtained from elastic He scattering data. Comparisons are made with the bound-state spectrum extracted from the measured resonances in the He scattering data and with the results of several other models used in the current literature. An assessment of the role played by higher-order dispersion contributions to the attractive potential is also included.