Due to the ancient, reviewed magic skill system that FoD implemented here (and can cause multiple issues, which is a completely different issue), the magic skill cap is indeed lvl 109, with no character ever being able to go even a single percent over lvl+9 magic.
In most cases it is incredibly detrimental to the point of folly, but it has been set up for both hightier balancing issues of the classes, and it was the start (and unbeknownst to FoD future development, also the end) of bringing some balance to PvP.
Shortly, as far as I have tested and know myself, the +9 (0%) magic cap is effective at all levels, and caps out at 109 at 100.