Would I be in trouble for sending out a global that said something like this?

"Interested in a clan? Try The Bomb Squad! /jo bomb"

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I think if you'd call it a "Huge recruitment event now!!" it might be legal. But just recuitment isn't really an event.
You could also make a bet server/ tourney under the name of /jo bomb and put in the motd something for people that want to join.

Making a global solely to advertise your clan is against the rules as quoted by cocacobra.

If your clan were to, for example, host a tourney or betting server or something the you can advertise that room/event in the global and then promote/tell people about your clan throughout the ingame event.