Channelers that choose Air as their primary sphere will receive Bind as their prime specific weave. Bind is a combination of the weaves wrap and gag, which wrap the target in flows of air to restrict movement and restricts the target's communication abilities.
Air prime channelers will have any of the remaining four spheres available to choose as their secondary sphere. The choice of secondary sphere strength, along with primary sphere strength, will determine the strength of weaves and stamina needed to cast.
For example, it is likely that a channeler choosing Air/Earth will be able to cast a better protection weave for less stamina than a channeler choosing Water/Spirit, or even Air/Water. However, Air prime channelers will need more stamina for healing weaves, which require high strength in spirit. Sphere strength and its effect on weave strength, duration, and stamina is complicated, and still being researched by the most experienced players.
Check the weaves page for the sphere strength of each weave.