You should not need to use a .stream file, or Stream Manager in order to play the stream.
RTMP based encoders publish or "Push" a stream to the Wowza server. Wowza will show a "publish" event when the encoder starts. Start Wowza in Stand-alone ([install-dir]/bin/startup.bat) mode, and start the encoder. Do you see a "publish" event?
You can also "pull" a stream into Wowza, say for example, from an I.P. camera, this is when you need to use a .stream file that points to the I.P. address of the source (I.P. camera), and Stream Manager to pull the stream to Wowza.