Several similar Unite Here strikes also took place in San Jose, Oakland and several other cities around the country. While many local unions have ended their strikes, Local 2 in San Francisco has not.
Marriott says the workers are well-compensated and has emphasized that its hotels are still operating well.
To replace workers at its San Francisco hotels, Marriott contracted with ESP.
In early November, several of those substitute workers told the San Francisco Chronicle they were not being paid for several days' worth of work. One of them later told the newspaper she was fired after speaking out about the issue.
Since then, three housekeepers have filed wage theft claims with the commissioner's office. Those claims, obtained by KQED, allege ESP did not pay workers the $17 per hour wages they were owed on multiple occasions, neglected to pay overtime and in at least one case, failed to compensate a worker for money he was owed after he quit.
Efforts to reach the three workers were unsuccessful. ESP has not responded to several requests for comment.
A Marriott representative emphasized the hotel chain's contractors abide by the law.
"Marriott's vendor contracts, including its contract with Environmental Services Partners, provide that vendors must comply with federal and state employment laws," said company spokesman Hunter Hardinge in an emailed statement.
The wage theft cases are part of a pattern, according to the union.
"We are disappointed but unsurprised to learn of yet another alleged instance of labor violations at a Marriott hotel under strike," said Unite Here press secretary Rachel Gumpert.
"Marriott is failing to behave as the industry leader it claims to be, and after separate allegations in multiple struck hotels, it's clear that Marriott needs to audit its contractors and ensure that temporary workers are not being exploited," Gumpert said.
The wage theft claims are set to be the subject of a settlement conference involving the workers, ESP and the state labor commissioner's office on Dec. 11.
"The goal is to have both parties try to reach an agreement to resolve the wage claim," said Paola Laverde, a spokeswoman for the Department of Industrial Relations.
While ESP is named in the claims, Marriott could also be held liable for wage violations, according to Fiester.
"If Marriott is benefiting from the fact that Environmental Service Partners are providing these services, there's a sense that Marriott has an obligation to ensure that these workers are being paid correctly," Fiester said.