Can I put a high voltage pulse on a low voltage bias?
Yes. See Operation Of The PVX-41XX and PVM-41XX Pulse Generators With Common Pulse (+HV) and Bias (-HV) if using same-polarity power supplies. Also, be aware that there will be a sawtooth waveform of less than 10 V that may become noticeable at low voltages. It's due to a refresh circuit and cannot be reduced.