connecting bulk propane to generator
I would suggest that you fit a second regulator to the supply from the large tank. This may sensibly require a larger pipe or the use of a different "tap" on the tank if there is one.

You should fit isolation valves so that you have full control over what is supplied when.

The second regulator is to avoid any restriction of the supply to either house or generator. You may well have to have some spark arrest devices by code depending on area and common sense suggests you should have them anyway.