When we run a binding, binding flow takes the Salesforce Account Record ID and places this in the custom field "AccountID" that you created in your QuickBooks Customer Object. Same field can be activated for Vendor object as well.  When you exposed that field (click on the Column title bar with the alt right button, then select "Customize Columns") and drag and drop this from Available to Chosen. This column will now show which Customers have been bound and if blank, Customers which are not bound.

The next step is to correct your Salesforce Account Name to match the QuickBooks Customer name - we will then rerun binding till all match.