SP is a grey area. If you read the UOB ONE CC FAQ
1. Excluded Merchants - Ministries and Govt Agencies like MOM, MOE, NEA, AVA, HDB, ICA, IRA, ACRA, etc ..... the last mentioned is "etc". SP is owned by Temasek Holdings which is own by the government
2. The UOB ONE card web advertisements - under utilities, only private retailers are listed - Diamond Electric, Geneco, iSwitch, Keppel Electric, Pacific Light, Sembcorp, Senoko, Sunreap. SP was not listed.
https://www.uob.com.sg/personal/index.page?lid=default-landing-pfs