Electric potential is the general term for the measurement of the energy that can be transferred per unit charge. It does not necessarily need to involve chemical processes. For example, you can generate an electric potential by rotating a wire in a magnetic field.
On the other hand the reduction potential is the electric potential that is generated when a certain species is being chemically reduced. So yeah, it is an "electric potential" of sorts, but as opposed to being a general term, the "reduction potential" refers to the electric potential that appears for a very specific process (chemical reduction).
I hope that didn't make things even more confusing