Citing an URL using the Waybackmachine (web.archive.org)
This should be fine, though editors get the final say. But since the web is volatile, it is pretty hard to cite a current page and hope that it will be there in a few years. The wayback machine was created for just this purpose.

Referencing potentially volatile information is always dangerous, and any such citation should be accompanied by the date the information was accessed, as you have done here. But the wayback machine (internet archive) is a series of snapshots that shouldn't change. 

Even worse than online information disappearing, is that it can be changed outside your control, making information you relied on say quite different things. 



And, for what it's worth, it is a good idea to donate a bit of money to such resources occasionally to help assure that they don't disappear for lack of support.