Not sure I understand your entire issue but......110psi supply is way too high. That does need to be regulated downward at the entry point immediately downstream of the meter. You don't want that level of pressure in ANY of your lines. That's one issue.

Depending on configuration and components in your irrigation system, you'll likely want those lines regulated down further with separate devices. Separate in-line PRV's for this purpose are commonly/cheaply available in irrigation-supply aisle of almost any hardware store. They usually take it down to 15-25psi for the irrigation lines.