  We compare quantitative estimates of the filamentarity of the galaxy
distribution in seven nearly two dimensional sections from the survey against
the predictions of LCDM N-body simulations. The filamentarity of the actual
galaxy distribution is known to be luminosity dependent. It is also known that
the filamentarity of the simulated galaxy distribution is highly sensitive to
the bias, and the simulations are consistent with the data for only a narrow
range of bias. We apply this feature to several volume limited subsamples with
different luminosities to determine a luminosity bias relation. The relative
bias $b/b^*$ as a function of the luminosity ratio $L/L^*$ is found to be well
described by a straight line $b/b^*=A + B (L/L^*)$ with $A=0.833 \pm 0.009$ and
$B=0.171 \pm 0.009$. Comparing with the earlier works all of which use ratios
of the two-point statistics, we find that our results are consistent with
Norberg et al.(2001) and Tegmark et al.(2004), while a steeper luminosity
dependence found by Benoist et al.(1996) is inconsistent.
