Glad you find it useful.
Here is my favorite (tiny) tutorial on arrays:
scirra.com/tutorials/360/generating-a-random-tile-map
For a quick-n-dirty way of doing things, have your "bullet-bubble" spawn an invisible Kill sprite, in all 8 directions around the "bullet-bubble" that kills all other bubbles of the same color.
Example:
Player shoots a RED "bullet-bubble",
bubble collides with another bubble, triggers the "bullet-bubble" to stop, RED "bullet-bubble" spawns a "Kill-red-bubble" sprite in all 8 directions.
When the stationary bubbles get hit by a kill red sprite, and it is red, it destroys itself, and spawns 8 kill-red sprites like the bullet bubble did.
This will cause a chain reaction, like puzzle bobble, but will leave some bubbles floating, and unattached. (in puzzle bobble, floating islands of bubbles destroys, and gives player score)