With the proliferation of electric vehicles and the deepened interdependence between power and traffic networks, tariff- and subsidy-based monetary incentives have been leveraged by network operators to shape vehicular&charging flow distributions to more closely align with network-level objectives. Travelers and network operators are generally regarded as two self-interested entities. As a result, the conflict between the system- and user-optimality usually forces travelers to bear an extra expenditure (either tariff payment or detour time) or requires network operators to dispense overmuch subsidies, both resulting in social welfare losses. The present work bridges this gap by designing a Cooperative Game based operation scheme that facilitates the collaboration between the two entities, in which collaborative travelers follow the social routing advice and then receive a certain level of reimbursement from network operators. To ensure a fair benefit allocation, we quantify the individual contribution as the difference of the path travel cost before and after the collaboration, then adopt the asymmetric Nash bargaining theory to settle the dispense of reimbursement. Numerical results on case studies indicate that the proposed model outperforms the subsidy-based non-cooperative Stackelberg Game in terms of promoting a win-win situation for both entities.