Were the Jokers (Impractical Jokers) fined for tearing money?

As far as I know, there were no legal consequences for the Jokers destroying that money. It's unlikely they even did anything illegal, and even if they did, nothing worth the federal government getting involved to punish them.

Technically, the bill wasn't destroyed. By US law, it's illegal to mutilate US paper currency "with intent to render such bank bill, draft, note, or other evidence of debt unfit to be reissued"^{18 U.S. Code § 333}. Tearing a bill cleanly in half doesn't render it unusable. As long as you have more than half of the bill, and as long as the bill is clearly a single bill (e.g. two halves with the same serial numbers on them), most places will take it, and any bank will exchange it for new money.

Even if they did destroy the money (e.g. burn it, a common movie trope), it's very rare for people to be prosecuted for destroying tiny amounts of money. There are plenty of new clips available where protesters clearly burn money on camera and are not charged with a crime.

In general, the purpose of the mutilation statute is twofold: prevent people from disrupting the economy by drastically changing the amount of currency in circulation, and prevent people from defacing currency as a means to cheat or scam others (e.g. cutting the numbers off a bill to hide it's true value, etc.)

Tearing a single dollar bill in half does neither of those things. At worst, the producers probably had to reimburse the true owner of the bill for his destroyed "property" and everyone just went on their way.