Once I am promoted to E3 because of JROTC, can I be promoted again before BCT?

I'm about to be a Senior in high school, and I enlisted in the Army Reserves in early July. I will be an E2 until I graduate, which would then put me at 3 years of JROTC, which would gain me a promotion to E3. If I participate in the refer a friend program, would I be eligible to receive a promotion to E4 before BCT?