To an extent.
What I mean by more surface area is contact with the heat spreader on the CPU and heat sink. NOT how thick the TIM is on the surface. By making it so that the TIM touches the entire heat spreader on the CPU, you are maximizing the area in which the heat can be transferred into the heatsink.
While TIM is a great thermal conductor, the shorter the route to the heatsink, the better. Like stated above, the TIM is meant to maximize surface area from the CPU to the heatsink. Use enough to cover the whole surface of the CPU, but not so much that it's gooping out of the sides (that would be a waste!). One of the biggest problems with asking for how much to add, is that each heatsink and CPU heat spreader can be greatly different, requiring different amounts. The Phenom II stock heat sink has a LOT of surface area, and in my experience, required a little more compound than I used on my previous Intel.
Don't stress too much over it, really. Unless you are going for top clock, your TIM application technique will really just be trivial, you'll see bigger differences in the quality of TIM.
If you'd like to do more reading, I found this interesting:
Goes through the different application techniques on different style coolers.Edited by SectorNine50 - 3/10/11 at 2:22am