Few follow multiple schools of thought regarding mantra meditation, and even fewer learn to reconcile the differences between them. You are among these rare heroes.
Benefit: You may activate and benefit from two mantras simultaneously. Meditating to activate two mantras at once requires a Concentration check 10 higher than normal (in addition to the sum of the increases the two mantras themselves call for, if any). Meditating to activate two mantras at once requires a full-round action even with Psionic Meditation.
Normal: You can only activate and benefit from one mantra at a time. Psionic Meditation allows you to gain psionic focus as move action.
Special: If you have the ability to expend your psionic focus while remaining focused (for instance, the Psicrystal Containment feat), you may end one of the mantras by expending your psionic focus while maintaining the other.