Hybrid systems coupling quantum spin defects (QSD) and magnons can enable unique spintronic device functionalities and probes for magnetism. Here, we add electric field control of magnon-QSD coupling to such systems by integrating ferromagnet-ferroelectric composite multiferroic with nitrogen-vacancy (NV) center spins. Combining quantum relaxometry with ferromagnetic resonance measurements and analytical modeling, we reveal that the observed electric-field tuning is consistent with the ferroelectric polarization control of the magnon-generated fields at the NV. Exploiting this mechanism, we also propose magnon-based hybrid electric field sensors which provide the possibility of improving dc electric field sensitivity of single-spin sensors.