The effect of the anisotropy of the interaction potential on ion-diatom non-adiabatic collisions is analized by considering the influence of the anisotropy on orientation averaged total cross sections for charge transfer in H++H-2(X-1 Sigma(+)(g)) collisions. We discuss the possibility of employing simplified methods such as an isotropic approximation, where only the electronic energies and interactions of a single orientation are necessary. The use of several isotropic calculations to evaluate the orientation averaged cross section is analized.