A Wowza support forum might be a better place to ask this question.
As far as a Roku player is concerned, I'm pretty sure all you would have to do is have a valid URL and a StreamFormat of "hls" in order to play back content from a Wowza server with the nDVR AddOn.
www.InstantTvChannel.com / www.InstantSubtitles.com - 717-441-4386 - Build a Roku SDK channel in 15 minutes! Easily and inexpensively generate subtitles!