A speaker is a speaker for the most part, though some are specifically designed as mains, centers, and surrounds. What are you outputting to the TV? There's no reason whatsoever that the TV cannot play stereo sound if the source is mixed for surround. My Panasonic plasma gets Netflix played to it and outputs the sound just fine.
What kind of connections do you have going to the TV? Does the TV itself have built in Netflix or is it being sent to the TV from another source (such as an Xbox, DVD or Blu-Ray, etc)?
Also, the first number in any speaker setup is the number of dedicated, full range sound channels. The . X refers to a dedicated subwoofer/LFE channel; so, 5.1 or 7.1 refers to five or seven full range channels respectively and one sub/LFE channel.