A Nonlinear Model Predictive Control approach to spacecraft rendezvous in non-Keplerian Lunar orbits is proposed. The approach is based on the Pontryagin Minimum Principle and allows the accomplishment of minimum-propellant maneuvers. The relative motion between the chaser and the target is described by the nonlinear and unstable dynamics of the circular restricted three body-problem. The discussed methodology provides a high degree of autonomy of the control system, merging into a unique algorithm the chaser trajectory planning and control in presence of nonlinear and non-convex state constraints. In the proposed formulation, the employment of a minimum-propellant controller leads to a bang-bang behavior of the control signal.