Even if there's no real reason to lunge, its a good skill for a horse to have. Allowing a horse to buck on the lunge eventually moves to bucking under saddle particularly if the horse is bucking towards the hander. Your horse is giving you the equine version of a middle finger salute.
How do you lunge?
If I have a horse that tends to spook, run or otherwise be stupid on a lunge line, I use a running inside rein. Run the lunge rein through the inside bit ring, and clip to the roller that is level or close to level with the elbow. You can get away with putting it one higher with a bucker, then you can keep their head up.
As soon as the horse goes to buck, I take up that rein to turn the horse's head towards the inside, and get after it with the lunge whip. It has to go forward with its head turned to the inside and will find it very difficult to buck. As soon as you see the horse relax again, release the pressure and go back to lunging.
None of my horses have bucked on the lunge using this method, even my very sensitive, spooky gelding is far more controllable on the lunge using this running inside rein technique.
I'd avoid connecting directly to the bit as you will either pull the bit through the mouth, or slam the horse in the mouth.
Avoiding lunging just to avoid this behaviour is useless. You can't ignore it.
Just like a horse that kicks, you can't avoid going near its back legs forever.
Fix the problem and you'll have a better, more respectful easyto deal with horse. Lunging is a very useful part of my training and I won't tolerate a horse that will not lunge quietly.