Tax Amount per line item does not show via SuiteTalk (web services)

Tax Amount field is seen when viewing the Opportunity Item List record and Sales Order Item List record on the SuiteTalk Schema Browser. However, since this is not viewable when accessing NetSuite UI, it is also not visible when accessing the record via SuiteTalk (web service).

As a solution, a custom column field can be added on the record that has the 'Tax Rate x Item Amount' formula that equals to the Tax Amount. 

An enhancement has already been filed as well and it is Enhancement # 165243 - Transactions > Sales > Enter Sales Orders > Gross Amount and Tax Amount columns do not appear on sales transaction forms.