The suit says Ramales and other staffers didn't get their proper share of a gratuity charge the restaurant automatically collected from parties with six or more diners.
The busboy also says he worked more than 40 hours per week without getting overtime.
A manager at the restaurant says the tip allegations are false, and all staffers made well above the legal minimum wage.
Publicists for Timberlake did not immediately respond to messages left Friday night.
