Looking at the manual for the 1150....no, you do not NEED to buy a separate streamer. To clarify, you can use any computer you have as a streamer. You can purchase TIDAL or Quboz or whatever streaming service you desire for access on your MAC or PC.
You may also consider Audirvana as the player. It is excellent but there are others but Tidal and Quboz can be used independently.
From your mac/pc connect to the 1150 via USB or it also looks like it has a bluetooth connection. Once you are connected you would point the output of the streamer on your mac/pc to that device instead of the mac/pc speakers.
You CAN buy a streamer is you so desire.