The Chip Bomb bet is a so called "advanced" roulette bet, in that you'll only really see it on premium roulette variants like Premier Roulette. But it's quite a simple bet. If you chip bomb 18, you make straight up bets on all numbers surrounding 18 on the number on the table plus the number 18. It's kind of like neighbours, except rather than betting on a number's neighbours on the wheel, you are betting on a number's neighbours on the betting layout.
If you bet on a number that sits on the one of the outside columns, you are going to be making a 6 chip bet. And if you "Chip Bomb" a number that sits in the middle column, you are going to be making a 9 chip bet. Bet on a number in the corner like 36 or 3, you'll end up making a 4 chip bet. The Chip Bomb (where you "Bomb the Number") is similar to the Number Combo Bet- the difference being that this bet consists entirely of straight up bets. Then you just hope that your chips don't go BOOM!
Roulette Table Layout Showing a Chip Bomb Bet on 17 (9 chip bet).
The Chip Bomb bet is another way of covering either 6 or 9 numbers, so if you make two 6 chip Chip Bombs (that don't overlap), it's another way of covering the same amount of table as a Column Bet or a Dozen Bet.
And if you make two 9 chip Chip Bombs (ie numbers in the middle column), this is another way of covering the same amount of table as you would with a even-payout bet like red or black. It just gives you another option of "mixing it up" a bit.
Roulette Table Layout Showing a Chip Bomb Bet on 18 (6 chip bet).
Not that it changes your odds one iota, but if we are playing startegies like the Martingale or Fibonacci System, and we are betting even-money bets like red/black, we like to mix up the bets from spin to spin, so we often switch to odd/even, hi/lo etc. The Chip Bomb is another way of mixing things up a bit, while still covering the same % of table.
And if you are playing systems that use columns and dozens (like the Law of The Third for example), then you can use 6 chip Chip Bombs to make up the same table coverage- again, mixing it up a bit. Just make sure that your Chip Bombs don't overlap- which they will do if you bet on adjacent numbers (on the table layout, not wheel).