You'll need to use the Manchester library. I'm currently in the process of writing a tutorial on how I got it to work. I'll update this post in a few days with the link if your still interested.
http://mysudoku.googlecode.com/files/manchester.zip
For both the receiving and transmitting ends. VirtualWire won't work with the tiny's. I came across the same problem. You can read more here.
On a side note, i couldn't get the github version of that library to work, so i'm using the older version, posted above.