I've researched this issue extensively and CPT defines the appropriate coding pretty well. The reimbursement will vary by carrier.
For 99070, CPT states ... Supplies and materials (except spectacles), provided by the physician over and above those usually included with the office visit or other services rendered (list drugs, trays, supplies, or materials provided). The key words in the statement are over and above those usually included with the office visit or other services . When the relative value (RVU) is assigned, it includes the value for supplies usually provided in an office setting. For example. laceration repairs are often done in an office setting and the supplies are included in the RVU for the repair performed in an office setting.
99070 should be billed in an office setting when the service would not usually be performed in an office setting.
An example I experienced was a newborn was brought into the clinic for a circumcision. Because this is not something that is usually done in an office setting, the supplies are separately billable.
Now, for the reimbursement. CPT Code 99070 has a B status indicator for Medicare, so don't count on reimbursement from Medicare. Check with commercial carriers for their reimbursement policy. I hope this is helpful.