Coming from sheep, wool is pretty "waxy" (lanolin) to begin with. I have an old heavy wool turtleneck sweater that I sail in and I seldom even feel damp when wearing it.
I'll bump this question over to the Softgoods forum. It may find a bit more specific answer there.
Lew Morris "It's what you discover, after you know it all, that counts." _ John Wooden
In all my years, I've only heard of wool felt being sold as is, never waxed.
As Lmo mentions, wool has natural oils in it (lanolin) which act similar to wax, in the sense that it adds natural water resistance (not 100% waterproof).
I'd suggest that if you really want waxed wool felt, you should pick up some Otter Wax and DIY. I think it would turn out pretty cool actually.