There are quite a few hotels/resorts with courts. Are you trying to find a pickup game? That's a bit difficult unless you want to pay the local pro to hit with you. If you don't like hotels (some are managed by Nikko tennis which of course runs the WTA tournament as well.
Try calling the Canggu Club or Bali Clay Courts. I don't have the numbers on this ipad but it's easily googled. Canggu Club is members only but you can pay for temp membership.
The clay courts are in pretty good shape but they require proper tennis shoes. Have fun!