What you did is called air layering...normally you scrape the stem area that you're going to wrap, apply a rooting hormone of choice and then wrap it...I usually scrape, apply rooting hormone then pack some slightly wet organic matter around the area and finally a plastic baggy cut open and wrap that around the cloning area and tie it with twist ties at both ends...you can monitor the root growth through the clear plastic baggy that way...what you have looks like the beginning of roots forming...I now use a bubble cloner and when I peak at the clones during a water level check I always notice bumps like that form just prior to roots showing up...g/l