PCI has the throughput of either 133 MB/s, 266 MB/s, or 533 MB/s depending on what bus you have on your motherboard (64 vs 32 bit, and what hertz your bus is currently compatible with).
PCIe is either 250 MB/s or 500 MB/s depending on whether or not you are running PCIe 1.x or 2.0
Wireless N (the fastest wireless currently available) operates at (about) between 6 and 16 MB/s
Wireless G (which you most likely own ) operates at 3 MB/s
What I'm trying to say is that the speed of the bus is exponentially ahead of today's wireless technology - go get yourself a good antenna
note: the wireless speeds I listed are speeds you'll actually see, not their claimed maximum throughput (which is STILL factors under the bus speed)