"Bonded Core" is ad-speak for plated bullets.
The major bullet manufacturers make thick-plated bullets vs. the thin plating on Berry's, Rainiers, and X-Tremes.
Some of these "bonded" bullets have ogives that requires deeper seating, and the deeper seating will raise pressure. Thus, if you are loading Gold Dots, for example, either verify that the seating depth is the same as a jacketed JHP or, best of all, go back to the starting load and work your way (as you are always supposed to do anyway).
However, if you a shooting a pure copper bullet (lead-free), then all previous reloading data is thrown out and you will need the manufacturer's load data