When a contact record syncs to Luminate via the RELO integration, it has a Luminate ID number added under "Aliases" so the best way to find records that have synced is to use that as the basis of a Raiser's Edge query.
  1.     Go to Query
  2.     Click New Query
  3.     Select Constituent as the Query Type
  4.     Select Dynamic as the Query Format
  5.     Click OK
  6.     For Criteria Select: Aliases > Alias Type > Equals > Luminate ID
  7.     Click OK
  8.     Adjust the Output and Sort Options if Needed
  9.     Click Run Now