it already depends on dev-lang/tk ... the X11 dep is superfluous.. also.. you nbeed to enable both the X and tcltk useflag to have the interface.. one would be more than enough.
I've simplified the dependencies to "X? ( dev-lang/tk )". However, I've found other ebuilds with similar duplicated dependencies, especially the "tcltk? ( dev-lang/tcl dev-lang/tk )". You might wanna fix them as well.