There is no iceberg or ice-themed zone in PokéPark Wii: Pikachu's Adventure. The game's areas are:
Ice-type Pokémon (Snorunt, Sneasel, Froslass) appear in Cavern Zone and Granite Zone, but there's no dedicated icy map. The sequel, PokéPark 2: Wonders Beyond, adds Cove Town (water/ice theme) but still no "iceberg zone."