DBAN does not recognize soft RAID arrays. If the soft RAID array is composed of individually exported disks, then DBAN will recognize and wipe each disk individually.
It is pointless to wipe a soft RAID array as a logical device.
The dban-1.0.3 release, and all releases prior, do not have drivers for real RAID hardware. Note that most Promise and Highpoint devices are not hard RAID implementations, DBAN can see the component devices attached to these controllers and wipe them individually.