I noticed the wording of the rules card didn't match the described intended effect of the card, so I reworded it to work as intended.
The original card text was "Trigger: If three or more balls are trapped inside, destroy this and all adjacent tiles" With the intended effect reading "The effect triggers when the three-ball rule destroys the tile, causing it to take all of its neighbors down with it. For best results, line up a few copies in a combustible conga line to set up a devastating chain reaction." Except as written it was a trigger separate from rule 2.1.5.5, could fail to explode if some of the balls were touching from the outside, and the chain reaction was basically just metatext.
The new wording "On destroy: destroy each adjacent tile." solves both of those issues, and is also short enough to fit on the actual tile instead of needing a card. It also explicitly means it explodes if any other effect tries to destroy it, such as the hammer tile or anything else. Personally I'm fine with that.
I've included both the errata'd card so you can "update" any already printed bomb tiles you have, and updated versions of the bomb tile that removes the trigger-indication-jagged bits, since it's no longer a "trigger", and adds the rules text to the actual tile. The difference between the two tiles is if the fuse cuts into the text or not, which you may prefer one way or the other.