By default, the Amazon importer will only import listings which are fulfilled by the merchant. If you wish to import your "Fulfilled by Amazon" items, you will need to update your import settings. Point your mouse over the "Selling" link in the upper left-hand corner of any page and select "Import from Amazon" from the drop-down. Click the link to "Cancel automatic inventory synchronizing," then show the advanced options. Check the box to import your FBA listings, then click the button to reimport your items.
Please note that if an FBA item sells on Bonanza, you will be responsible for informing Amazon to fulfill the order (this does not happen automatically).