You have 2 questions: what really is an 'interbond', and what is the best bullet to whack a 500yd Ram. The first is a real easy one; the 2nd will have a lot of opinions. An 'interbond' is nothing more than a lead core soldiered to the jacket. There is no magic to this, thou the results are huge. The molecular bond between the lead and jacket causes at least a 92%, often a 98%, weight retention after the bullet plows thru it's target. It mushrooms, but doesn't separate. Very efficient. Almost makes partition, or semi-partition bullets obsolete. And, from the producer's point of view, a lot more easier to make. The technique is to apply soldiering flux (an acid) to the inside of the jacket, drop in the lead core, heat to melting, let it cool, wash away the residue flux, swage the lead tightly into the jacket ( it will stick to the copper where unsoldered lead cores wouldn't), and then swage the nose shape. Some companies call this "Core Bonding".
Core bonding in itself won't affect accuracy one way or the other as compared to a similar bullet without bonding (as long as the core is solidly swaged in). If you heat up a formed bullet and let it cool, that may affect accuracy because you've changed the temper of the copper jacket, and if any of the core melted out of the bullet, the weight not only would have changed, but its mass semidry would also be (probably) off balance.
It's the external shape of the bullet, it's BC and CG, it's velocity and weight, the twist rate and length of the barrel, the sighting and holding skill of the shooter, and much more, that comes into play, not whether the bullet is core bonded, partitioned, wasp-wasted,or whatever, that will put you on that Ram. If we were talking about terminal ballistics, what happens when the bullet hits and then effects the target, then the bullet internals are very important.