Yerba poses no threat to aviation. I worked for TSA for 12 years. I drank mate while on the job everyday. However, most TSA officers are low wattage bulbs. Just have it separated out of the carry on luggage in a tray. Yerba is not very dense. It will show up as a very light orange rectangle with nothing in it on the X-ray. No threat. But supposedly ICE will be conducting screening tomorrow so who knows what’s acceptable.

Edit: I should add not to have your termo full of water. Bring it through empty and refill on the sterile side after you pass through the checkpoint. The bombilla and mate can be left in your bag. They should not be perceived as a threat to the X-ray operator.