(TP)Yes. Now you may ask why on earth would M. have engaged in military activity across the Black Sea from his own kingdom, but one would have to answer that question also if one, with tradition, assumes that that activity started with appeals from Khersonesos or the Bosporan Kingdom.
****GK: Tradition holds that there was a defensive treaty between Pontos and Chersonesos since the time of Pharnaces I (either from 179 BCE or 155 BCE). That is what Chersonesos appealed to when requesting military assistance from Mithradates against the Scythians.*****