I just check on Amazon for the ULM100USB. and in the Q&A someone from Behringer said that it works on Macs. Have you contacted their customer service department?
Recommendation: Given that their website and product brochure says that it's compatible with a Mac, you should stick with that product.
From their product brochure:
I would double check the specs, or clarify your question because everything I am finding says this works with OS X (and I can't see why it wouldn't).
As for bluetooth and WiFi
I seriously doubt that you are going to find a pro level mic that transmits over either of these technologies. Why?
Bluetooth is limited to 30 feet and a PC/Mac will only work with one bluetooth audio device at a time. This makes it rather impractical to develop a wireless mic system when you can only have 1 mic paired to 1 computer and you can't go any further than 30 feet
WiFi gets around the 30 foot limitation but the audio quality will be horrible. WiFi is wireless IP which is packetized. So forgetting about the DAC (digital audio conversion) that must be done, it will then take those digital signals and put them in packets, blast them out over the network to the receiving device, reassemble them, convert them back with another DAC then process them.
Shorter version of that? Think VoIP. It's really neat from time to time but it can get horrible quick the moment there is a traffic storm. Why would any company build a product for which the quality will inherently be crap due to facts completely outside their control. The answer is...they won't.
The "radio based stuff" as you called it works off a 2.4Ghz channel which it dedicates to that particular mic. This way you can have the range of 2.4Ghz and the high quality of a clear signal that it isn't in competition with other mics for bandwidth.