I swear in a previous version of the firmware, I was able to filter just my wireless MAC addresses. After updating to 1.32, it apparently went away. However, in the help, it still mentions the ability to filter either wired or wireless, so I think they took this out.
My other routers (Linksys, Netgear, Apple) all had the ability to filter only wireless clients.
I have a lot of machines and devices (like phones), and so this is a problem for me, too. I would prefer to limit access to wireless only, and not worry about the wired connections.