Can You Cross-Play Call of Duty: Black Ops (Wii) with Xbox Live? No — Separate Networks
No. Cross-platform play did not exist in 2010.
Wii Version: Developed by Treyarch on a modified World at War engine. Uses Nintendo Wi-Fi Connection (WFC) (shut down May 2014). Peer-to-peer hosting. No DLC support.
Xbox 360 / PS3 / PC Versions: Run on Demonware/IWNet (dedicated servers for PC, listen servers for console). Different netcode, different authentication, different content (DLC maps, modes).
Wii-Specific Limitations
No Combat Training (bots).
No Theater Mode.
No DLC (First Strike, Escalation, Annihilation, Rezurrection).
Reduced player count (12 vs 18).
Lower textures, no dynamic lighting, simplified shaders.
Playing Wii Black Ops Online Today
Nintendo WFC is dead. Options:
RiiConnect24 / Wiimmfi: Community replacement for WFC. Requires Wii homebrew (Letterbomb/str2hax) + Wiimmfi patcher. Works for Mario Kart Wii, Brawl, GoldenEye, Black Ops (partial support).
Dolphin Emulator (PC) + Wiimmfi: Best experience (1080p/4K, 60fps, keyboard/mouse, cross-play with real Wiis).
Bottom Line: Never cross-play. Wii version is a distinct, inferior port on a dead network. Revivable only via homebrew.