Yes, as mentioned the range depends on power. There are some details to understand though. The amount of power that gets out of your transmitter and into the air depends on the efficiency of your antenna. The amount of power that goes in the direction you want depends on the ability of the antenna to focus power in a particular direction. We call this the directivity of the antenna. Each wireless connection involves two antennas, one at the transmitter and another at the receiver. The antenna behavior at both ends of the link both affect the range.
The range is also a function of frequency, but doesn't change much from 88 to 108 Mhz. The range is also strongly affected by the distance from each of your antennas to the surface of the earth.
In the radio world, we often find that it is cheaper to make a better antenna than it is to try and get more power out of our transmitter. Many amateur and beginner transmitters actually generate enough power but have bad range because of a poor antenna.