There are two ways which i can think off to make your tags hit the correct document, on of them is to send the DocumentNo in the PML which is carrying the tags data to AII from your device controller. XML for this can be obtained from the test tool TCODE(/AIN/TEST_CLIENT). In the filed name on the info tag give DOCUMENT_NO rest remains as previous tests. Once you view the XML you'll see DOCUMENT_NO element come just above the READERID element in the PML.
Second method is to go to AII desktop and assign the delivery document to a specific location, after assignment all tags read from that location (all tags read by devices configured on that location) will be bound to your delivery. You can observer the assigned delivery being associated with the tags in the Execution view.