Firefox has supported transform-origin on html elements since version 16 (even earlier if you count -moz-transform-origin), but it’s been a bit hit and miss using it on SVG elements.
Percentage units on SVG elements did not work at all, neither did center of course since that’s just an alias for 50%.
Fortunately that’s all about to change. Firefox 41 and 42 have a new pref svg.transform-origin.enabled that you can use to enable transform-origin support for SVG elements. Even better, Firefox 43 will not require a pref at all, it will support transform-origin straight out of the box.