Tuplet Bracket delta-y

[John Krajewski]

I am using Lilypond v 1.4.5. under cygwin on Windows 2000 and would like to
say thank you for producing such a fantastic package, I am amazed at the
beautiful output it produces. I have only been using Lilypond for a couple
of weeks and am gradually getting to grips with some of its finer points.

I do have a small problem with the vertical offset of a tuplet bracket which
is partially obscuring a tenuto above one of the tupleted notes. I have
tried to raise the bracket above the tenuto by setting the delta-y property
(as below).

\property Voice.Tie \set #'direction = #+1
\property Voice.TupletBracket \set #'delta-y = #2
< \) f,4 aes4 > ~ \times 2/3 {aes4 bes'8^\tenuto}
[aes16^\tenuto \(f ges aes]

The tuplet bracket does not move and there are no apparent errors during
compilation.
Have I done something silly here or is this feature not supported yet?

Best Regards,
John Krajewski.