This posting is older than 6 months and can contain outdated information.
If OS X Bluetooth stack requests a PIN from you, it's usually because it doesn't have correct info on file for your device.
You can usually fix this issue by removing the bad info from the cache of the OS X Bluetooth stack. The process for the Sony PS3 BD Remote is detailed here:
https://www.iospirit.com/support/faqs/remotebuddy/category/14/Hardware-Sony-BD-Remote-Control/entry/246/-/
These instructions were created with the help of Apple, to whom I've reported this issue - mostly in connection with the BD Remote - numerous times over the years.
If you replace "BD Remote Control" with "Nintendo RVL-CNT-01", the same steps should work for the Wii Remote.
Please let me know if it helps.