The following GL Entry is created when a Shipment Receipt is Posted:
CR - Liability Account: Accounts Payable
Each product has a Inventory GL Account associated with it.
The default Accounts Payable account. This account can be changed to a different account in Setup, Entity Setting, Shipment Receipts, Credited Account for New Shipment Receipts.
When a bill is created and linked to the shipment receipt, the system would reverse the entry made at time Shipment Receipt is posted and then post a new entry using the amount that is on the bill that looks like this
CR - Liability Account: Accounts Payable for Selected Supplier