interstate endorsements

Hello All!
This is my first-ever thread, just found the site yesterday.
So if I posted this on the wrong forum, I'll appreciate the staff to move it on the right forum.
I just wanna seek some info from those nurses who used the interstate endorsements.
I'm not a US-RN yet but I'm totally working on that.
I applied for licensure at VT though at that time, I was still practicing nursing in my home country, Philippines.
But things changed and I got married and entered US last Feb. Took my NCLEX last March and failed with 75 q's.
I currently live in PA, and submitted my papers for retake to VT this month.
I thought that all states are participating the Nursing Licensure Compact, unfortunately, it wasn't.
I read at the PA BON's site are mentioning about the State Endorsement thingy.
Can anybody explain it more to me and what does it do?
Will they accept my VT license when working if I passed the NCLEX this time?
You replies would be greatly appreciated!
Thank you!