There's only way to find out, test it. Real world wireless G performance never comes close to its rated spec (54Mbps). Those are only theoretical numbers produced in laboratories under perfect conditions, and doesn't even consider network overhead, it’s just raw bits. A more realistic number is perhaps 18-24Mbps. But that can vary a lot depending on distance, obstacles, interference from other 2.4GHz devices, etc. So you're a borderline case, and only testing will reveal the answer.
Of course, if you need better performance for local (i.e., machine to machine) connections, you need either wire, or a wireless N router.