Just because the base is in Singapore it may not mean the flight attendents are Singaporean. Could someone confirm the nationality of the crews ?
Flight attendents working in Singapore are multi national and include Malaysians, Thais, Indonesians, Philippinos, Vietnamese and mainland Chinese.
Even a Singaporean f/a not working for SQ would only be on around SG$2000 a month, plus possible commission on sales.
Also do the F/As hold ASIC cards as they are accessing restricted areas at Australian airports ?