I've added a Planet Improvement mod to the library called the Cheat Station. Some of you may remember it from GalCiv1. I made this in my original attempt at porting the Enhanced Terraforming mod, and it contains all the planetary bonuses I could find.
I haven't been able to identify what all the bonuses do, but most of them are labelled in the xml file so you can use this as a template or "cheat sheet" for making your own mods.
Plus, it also functions as an easy to use cheat that both you and the AI can use.
ps. If it dosen't get approved for the library, I'll post it somewhere else and add a link to it at a later time.