The FCC-ee project is undergoing a review and redesign of the injector chain. The FCC-ee injector complex accelerates electron and positron bunches up to an energy of 6 GeV using linacs before injection into the pre booster ring. The option of extending the linacs to inject into the booster ring at 20 GeV directly is also being analysed. Multi-bunch operation is being considered as an option to speed up the filling time of the rings. A study of the impact of short- and long-range wakefields in the case of single-bunch and multi-bunch operation, based on the experience developed in the context of CLIC, is presented.