In this work, we have evaluated the accuracy of the eb-MBE and of the db-MBE recently developed in our research group, for ion-water clusters. With the conventional eb-MBE, the errors in the total and relative interaction energies of these systems are significantly larger than for neat water clusters, mainly because of the large polarization effects that are induced by the ion. Thus, ion-water clusters present a very challenging test case for the db-MBE. To avoid the steep scaling of the computational effort with cluster size that plagues higher-order MBEs, our goal is to achieve sufficient accuracy already with a two-body expansion.