I can usually sneak 1/2" lines past an 1 1/2" or even a 2" drain line in 2X4 wall. Sometimes it might require a bit of creative piping, but usually if I plan and drill my holes correctly, it isn't to much of an issue.
That said, the answer to your question is, it depends. The farther the distance to the other lav bowl, the less likely I would be to run supply line to it. The reason being, you might have some problems with shaking and rattling supply lines when you turn the faucet on and off. Of course, you could find some type of clamps to secure the lines to the back of the cabinet to prevent this.