Rock Band PS3 Guitar on Wii: Incompatible (Bluetooth vs Proprietary)

No, the Rock Band PS3 guitar won't work on Wii.

• Connectivity: PS3 guitar uses Bluetooth; Wii uses proprietary wireless.
• Input Methods: Different button layouts/sensors—PS3 has pressure-sensitive buttons, Wii relies on strum/button presses.

Even if connected, the game wouldn't recognize PS3 guitar inputs correctly. You need a Wii-specific guitar for Rock Band on Wii.