No, it is not treated as a cash advance.
Sniip is an authorised BPAY Payer Institution Member (PIM). The process is simple: Sniip receives the payment for the bill from a user and once these funds have cleared, Sniip processes that payment on your behalf via BPAY.
Because the funds are cleared as a payment to Sniip, it is treated as a normal credit card purchase, not a cash advance.