More than enough bag.
Honestly, a 40F bag is all you need. Most of our scouts had 40F cheap bags in mid june.
The lowest expected temps in early june, at highest elevation camp (Mt Phillips) would only be about 30F. Add clothing and sleep in a tent, and you have that covered easily.
The rest of the time, you will sweat under a 30F bag.
You dont need boots for Philmont, or darn near anywhere else for that matter, unless you are carrying a very heavy pack. And then its for support underfoot, not mythological "ankle" support.