Yes, that's what wave amplitude means. It is the max displacement from the mean position.
For a surface wave on water, the mean position is where the surface would be if not for the wave, so the amplitude is the height of a wave crest above that.
For a longitudinal wave, such as an air column in a pipe, each molecule is oscillating back and forth parallel to the axis of the pipe. For a given molecule, its amplitude is its maximum displacement from its mean position. The molecules with the greatest amplitude will be at the antinodes (unless I've confused nodes and antinodes again).
In general, we can write a traveling wave as y=A sin(kx-ωt), for suitable choices of x=0 and t=0. y here is the displacement of the particle at position x at time t. The velocity of that particle is therefore Aω cos(kx-ωt), and its peak speed is |Aω|. So its peak KE is as (Aω)2. For a given frequency, the energy content is proportional to the square of the amplitude.
It is also interesting to consider interference. Where waves cancel the amplitude is zero, and where they maximally reinforce the amplitudes add up. If the energy were only proportional to the amplitude we would find that the total energy over the area must be less than the sum of the energies of the individual waves. But because it is proportional to the square of the amplitude it turns out that the integral over the area gives the same energy as by adding the energies of the two waves.