A GEDcom uploaded to Rootweb WCT CAN be viewed and searched from Ancestry.com.
It doesn't appear as a Public or Private Member Tree. It is in Ancestry World Trees, AWT.
To find AWT in Ancestry.com:
1) Hit SEARCH bar
2) Hit FAMILY TREES tab
3) Look on the right side of this page, see 2nd box "Browse Records".
4) In "Browse Records" box, see "Family Trees: link and hit that.
5) On this page, scroll down past the search box, on the left side see "Featured Titles in this Category:"
Personal Member Trees
Public Member Trees
Ancestry World Tree
6) Hit "Ancestry World Tree"
7) You're now on a page that will search Rootsweb WC Trees.