I did some studying on the sex-links a few weeks ago when I was asked if Cream Legbar Males that over Black Copper Marans females would produce sex-linked off-spring.
What I have found is that any gene that is located on the Z chromosome can be used for a sex link. this included barring (B and b), silver (S and s) , foot color (Id, and its corresponding alleles), slow feathering (K and its alleles), etc.
The trick is for the Male to be homogygus for the resessive gene (the lowcase letter). This would be b/b, s/s, etc. If the males is B/b, S/s, B/B, S/S, etc, the link won't work. If the father doesn't have the silver gene (s/s) and is red and the mother is silver (S/-) then the male off-spring will be all Siver (S/s) and the femlae off-spring will all be red (s/-).
Note: Sex-links do not breed true. Bother x Sister parings would have both male and female of spring of both colors. In the Cream Legbar the Autosexing comes from the barring gene. The double barring in the males (B/B) over the duckwing pattern shows up differently than the single barring of the females (B/-).
The barbanter appears to be a spangled breed and so any barring that it might have would be an autosomal barring (caused bu a combination of modfiers rather than a single gene) and would not be sexlinked.
The Legbar Cock X Barbanter Hen would be [B/B] x [b/-]. so the males would be [B/b] which would be single barred and the females would be [B/-] also single barred. I have been wrong before, but this does not look like it should produce a sexlink.
By-the-way...what color Barbanters do you have? Cream?