Does an 64 X2 4800+ bottleneck and 8800GT?
Depends on the application and your resolution.
At lower resolutions, the GPU has much less work to do, therefore the CPU becomes the bottleneck, increase the resolution and the CPU bottleneck diminishes and is eventually limited as the GPU has to do more work and becomes the bottleneck.
It depends on the app. as well, some are more CPU intensive whereas some are more GPU intensive.
Overall it's a decent combination, though.