There should be a sticky for this question. A search will show lots of threads.
The short answer, shore power is referenced to ground. Portable generators or inverters have no reference to ground. They don't even have a neutral. They have two wires, either one could be defined as "Hot" or as "Neutral". You could bond the "neutral" to generator chassis/receptical ground. It won't make the MH any safer. In fact, the MH will become less safe. With no bond, it takes two faults to get shocked. It takes just one fault to get shocked when bonded.
