Hi Snakelady
Yes they are closely related, they are in the same genus and occur in the same region.
Being a small elapid not much is known their venom. But I know that their bite is extremely painful and knocked my friend around for a few days.
Secondly a study was conducted not too long ago on Suta punctata and Suta suta.
Their venom is considered nearotoxic and myotoxic.
The study concluded with the statment that with the polyvalent antivenom, which is the only antivenom appropriate for Suta sp. does not reverse the venom as efficiently as previously thought.
Whilst they are a common small elapid they should not be underestimated.
Source
Kuruppu S, Robinson S, Hodgson WC and Fry BG.