I don't know, but I've found interbond and sirocco II bullets very difficult to load. I've tried them in different calibers and rifles and haven't had very good groups. On the other hand, berger, SST, A-Max, ELD-X all had worked great on most of my rifles. Never tried accubonds so I can´t say anything about them, but interbonds and siroccos had given me a very hard time. They perform great on game but not very accurate on my rifles.You've been shooting the wrong bonded bullets then or not spending enough time working up a load.
There's nothing at all inherently accurate about a bonded bullet and they will fly the same as a comparable non bonded bullet of the same caliber, weight, form factor etc.
Maybe, as you say I need to spend more time working up my loads, but I'm not a big fan of wasting expensive bullets, powder and barrel life on working up a load. If it seems promising, I twitch it a little bit to make it better, but if I see 2.5-3 MOA groups from the beginning, i just don't waste my money trying to make the bullet work.