Whether service tax or TDS is applicale

Hi all,we have two concerns of two relatives .one person  is headof one bussiness and other is head of transporting business.As they are relative so all the transporting bill of first concern is paid by second concern later we pay the actual amount paid by second concern for transporting bill to the second concern. even the transporting bill is in the name second concern. Now my question is in this transection who is liable toservice tax payment under GTA? also is first concern should cut TDS  on amount paid assuming there is contract to pay the transporting bill?