I'm skeptical about your rig. Portable gens do not have to bond neutral and ground for starters.
ALL of my equipment has their ground bondeds including the frame. The transfer switch for the gen and the inverter switch the neutrals and the hots and hence the common household test shows 3 green lights and I would not want it any other way.
I'd bet a donut Alliance says it's OK. And since there are absolutely no code requirements or insptections for a RV they are correct. There is a recommended paractice for RVs of course...