Bookkeeping report that includes grouping by deposit and Line Item Totals
This is not an iATS Payments extension issue. Payment Processors like iATS Payments process the total amount - the details of how the total amount was arrived at - are within CiviCRM.

CiviCRM stores the line items in the the civicrm_line_item table it contains an entity reference to the civicrm_contribution table -> which has the trxn_id (Transaction ID). 

So if you want to group by lineItems as opposed to by contributions you'll need to combine these two tables - and sum up the lineItems over a specific receive_date range (and/or for specific trxn_id-s).