\version "2.18.2"
\relative c'' {
% print bend after mono-voice note Great! %
<c a>2 c2-\bendAfter #+4
%%%%
% no bend printed over chord-voice %
<c a>2-\bendAfter #+4 c2
%%%%
% Works in poly-voice but diferent structure No '#' and No '+' but Yes '-' %
<<
{c2-\bendAfter 4}
\\
{a2-\bendAfter -4}
>>
c2
%%%%
% after first apply to chord, no bend's printed again in signle voice %
<c a>2 c2-\bendAfter #-4
}