If the situation is such that longer range only means lower received signal to noise ratio, then the answer is generally yes but there are many variables undefined. For example the range may be limited by frame length and turn around time. If your radio is already waiting for a reply after sending a packet, data rate is limited by timing not signal level. The amplifier needs to sense transmit / receive state without reducing packet rate. If full duplex the amplifier must not introduce noise into the receiver.
as a general rule, you will gain only a single `S` point for each doubling of power, so for instance you`re pushing 1W out, you`ll only get 3db gain (3`s` points) for pushing 4W, perhaps you may be better with a directional beam like a Yagi or Cantenna (depending on the frequency you`re thinking of of course).
The antenna gain solution is much better because you dont need to switch the amplifier from transmit to receive. Being passive, antenna gain is more like actually reducing the range. If the link is line of sight (sometimes called R-squared propagation) you should get a doubling of range for each 6dB antenna gain you put in there.
