Mark, you said "fields of energy are not made up of any solid matter" even though you are correct in saying that in the area of electromagnetic propagation I'm not sure it applies in the way you think it does. You also said..... " it can be bounced or reflected off from certain things " that is true also, but you are forgetting bending it or refraction.
Light also holds no mass and is not solid matter yet we all know that it can bend when encountering different density of material. Light is also considered an electromagnetic wave so according to you it should only "bounced or reflected from certain things" and not be affected by wind. Atmospheric disturbance is what causes stars to appear to twinkle. That is light being affected by the atmosphere, atmosphere = wind my friend.
Back to radiowaves.... Radiowaves are the same as light in being electro magnetic wave albeit much longer in wavelength. Being longer in wavelength it is less prone to interference. A 14khz electromagnetic wave will penetrate earth while a 400thz electromagnetic wave (light) will be blocked by a single leaf. Having said that, the atmosphere, wind, also affects radiowaves albeit to a lesser degree than light. Read up on propagation and refraction of radiowaves here http://www.mike-willis.com/Tutorial/PF6.htm
Now, what is being discussed was eletro magnetic interference. Having established that wind to varying degrees can affect radiowaves, interference is a whole different level of complication. Wind can cause interference in many, perhaps countless ways. Maybe it affects the propagation of the radiowave itself directly (speculation) in that it's area of effect shifts slightly with wind variance. I agree with you that this is unlikely (in this narrow scope) but disagree with you that it's impossible. The effects are there, very measurable (in larger scope) and any shortwave guy will enlighten you as to atmospheric events affecting who you can talk to and when via shortwave. Wind can affect things other than the radiowave itself and cause even greater interference. How about more speculation.... Wind affecting powerlines in that with wind they sway slightly. This affects the relationship of one powerline to another that in turn affects attenuation (signal loss). The field emitted by those powerlines will shift in turn it's area of effect will shift. So, on a calm windless day the interference caused by powerlines for conversations sake extends 300 yards from the powerlines. On a windy day the powerlines shifts randomly, therefore the field and area of effect of the interference can become 200-400 yards and continues to shift as long as wind happens. This speculation is based on the relationship of one powerline to another and it's emitted field.
Another possibility is grounding or isolation. High tension powerlines are isolated from ground but that isolation is not perfect. Leakage is unavoidable and the leakage from the cable to the tower keeping it up is substantial. That leakage are from cables that hold 10,000+ volts and tens of thousands of amps. Those leakages can come from the insulators, a tree that's too close, dust, a bird sitting on the cable, the possibilities are countless. So the strength and frequency, lobe shape, etc of the field that is causing interference is just as countless and just as random.
So, what I'm getting at is the possibilities of interference is incredibly complicated and can come from countless ways and sources. Wind affects the radiowave/field itself (admittedly minorly) but wind can and do affect just about anything else in our world that does emit radiowaves and cause interference. One calm day on one spot on the ground interference does NOT happen. Wind picks up and the same spot interference does happen. Not only is this plausible, but it is foolhardy to automatically say wind cannot affect interference based on a single and wrong assumption that radiowaves being massless cannot be affected by wind therefore interference cannot be affected by wind.
P.S. Just a disclaimer, I'm just a regular lay person and what I've said are just my personal understandings and I could be COMPLETELY off the mark so take it with a lump of salt.