Hm, interesting question...
You will need something like this:
http://www.amazon.co.uk/Emprex-AWV-698B-5-8Ghz-Wireless-sender/dp/B001JJDC88/ref=pd_cp_ce_0 (One of the reviewers said it worked with game consoles).
Or this:
http://www.goldenshop.com.hk/AI-trad/Misc_htm/m_24gwtran.htm (Says it works with consoles but the shop is in Hong Kong and the ordering process seems a little wayward to be honest.)
A few words of caution before you purchase though: Those transmitters frequently get disrupted by other wireless signals, so if you are using a wireless router, cordless phone, or even a microwave, you can expect static or even complete loss of picture.
There's also the Wii itself to think about. If you have wireless Internet, the transmitter could interfere with the signal meaning you probably won't be able to get online. Also, you would need the sensor bar to be above/below the TV you play on. This might require you to purchase an extension cable for it (might not be practical), or to get a replacement wireless sensor bar (which will also probably conflict with the transmitter).
Also, the Wii Remotes are connected to the Wii via Bluetooth meaning you still need them to be close to the console (within 10 metres), and that you have yet another signal that will probably conflict with the transmitter.
Given the logistics of it all and the high chance it won't work properly, it might be better to just move the console around, but good luck if you decide to go with a transmitter.