If so, are transactions that occur at KoinWorks allowed to use Bitcoin?

The short answer, no.

The full answer, the monetary authority forbids.

The ban by Bank Indonesia (BI) is intended for technology-based financial service actors (KoinWorks, one of them) including e-commerce, so as not to accept bitcoin.

Virtual currency processing is also prohibited.

According to the Head of the Communications Department of Bank Indonesia, Agusman Zainal, "In the context of the payment system, bitcoin is not a legal tender."

He added that this had actually been regulated in the Bank Indonesia Regulation concerning the Implementation of Payment Transaction Processing in 2016.