Can my boss punish me for reporting sexual harassment at work?

Based on the facts you provided, your manager's actions appear to be a direct violation of the law regarding victimisation. Victimisation occurs when someone is punished or threatened with punishment because they made a complaint about discrimination or harassment. Specifically, the law states that a person commits victimisation if they "subject, or threaten to subject, the other person to any detriment on the ground that the other person: (a) has made, or proposes to make, a complaint" [cite:au-sex-discrimination-1984-sec94]. In your case, your manager has threatened to delay your pay cheque and cancel your overtime shifts—both of which are financial and professional detriments—specifically because you filed a formal complaint about a colleague's sexualised comments. Furthermore, your employer has a "positive duty" to take "reasonable and proportionate measures to eliminate" certain types of misconduct [cite:au-sex-discrimination-1984-sec47c]. This duty includes preventing "acts of victimisation... that relate to complaints" [cite:au-sex-discrimination-1984-sec47c]. Since you have already informed HR and they have not stopped your manager from threatening your livelihood, the firm may be failing in its legal obligation to protect you from these retaliatory actions. It is currently uncertain whether your manager's threats will be successfully defended by claiming the complaint was made in bad faith, but the law provides a defence only if it is proved the allegation was "false and was not made in good faith" [cite:au-sex-discrimination-1984-sec94]. If your report about the morning tea break comments was honest, this defence should not apply to him.