Female dehane may have a little red under the eye like the male does. So will most of the females of the reddish 'spotted' taeniatus, but this color is mood induced. I would not use the stripe as a distinguishing characteristic, because the colors in these fish are somewhat variable, and other geographic forms have the red also (specifically looundje). However, the red might be valuble to distinguish dehane from bipindi, if you are 100% sure you have one or the other. In my experience the bipindi males have a darker edge to the body scales, creating a more 'scalloped' look that other taeniatus. The male bipindi also show the lateral stripes more regularly that other taeniatus. Most taeniatus show them in stress/aggression situations, but bipindi seems to wear them when not stressed nor aggressive. The picture of bipindi (page 189) in Anton's book is a good indicator of what bipindi looks like most the time. Female bipindi, when courting or defending a territory, have a pearly white abdomen offset by a dark purple, almost black, color around the abdomen. Dehane has a pinker belly when displaying.
These are just my aquarium observations... these fish are highly variable even within specific populaitons, so someone else may being seeing something different.