A witness who is not a party to the proceeding and who is subpoenaed to appear at a deposition or hearing or to produce documents, records, or other tangible things, shall receive reimbursement for expenses incurred in complying with the subpoena. Reimbursement shall be based on the minimum set forth in the Administrative Procedure and Texas Register Act (APTRA) or the State of Texas Travel Allowance Guide issued by the Comptroller of Public Accounts, whichever is greater. Said amount shall be paid by the party at whose request the witness is subpoenaed.