I've always been under the impression that a team if it has not payed a roster bonus does not have it count against their cap space.
If this is untrue, it's stpuid and makes the incentive to pay any roster bonus to a player virtually nill. I'd almost never pay a roster bonus if I were a GM. I'd either re-structure it again or guarantee it.
If the thing is going to count anyway, might as well push it into the future when you either are rebuilding or don't need as much cap space.
Many teams in their rebuilding years do not use all their cap space anyway.
If they have to count an option bonus now that hasn't even been paid yet, that's just dumb. Why wouldn't it count when it was actually paid?