Hey Glenn,
The frequencies of DECT and Bluetooth are known. These frequencies do not interfere with those of WiFi.
It is unlikely that your wireless headset could disturb the Onefinity Controller, EMI is more likely to be emitted by the Onefinity CNC machine, especially by the router with its carbon-brush commutators, or unsufficiently earthed machine or spindle or VFD.
However the cables to the stepper motors are not shielded. If you want to run spindle or router cables in parallel to them, I would replace them by shielded and correctly grounded cables.
See also Proper Grounding - How have you grounded your frame? and Material and Tools needed for grounding the CNC machine for details.