Used a chemical on my MacBook screen. Now what?
You may have damaged the coating on your MacBook Air Screen.  Chemicals "strip" the protective coating that's applied to the glass.  It's like if you peeled some of the tint on your car window; you can't wipe it back on.

Monster includes a PDF "manual" which is available on their website's support page.




  If the product to be cleaned stipulates "soap and water" cleaning only or
  recommends that no cleaners be used on your product, do not use this
  cleaner as a cleaning method.


As, as pointed out in the comments, Apple says to dampen a soft cloth with water only.


  To clean the screen on your MacBook, MacBook Pro, or MacBook Air,
  first shut down the computer and unplug the power adapter. Dampen a
  soft, lint-free cloth with water only, then use it to clean the
  computer's screen.


Bottom Line

You probably damaged the protective coating.  You may be able to "polish" the streak out by completely removing the protective layer, but this is just conjecture at this point.