The Secondary Vermispicer Grips do not change the range. Base range seems to be 10 meters for tentacles to "latch" on.
Gibber does not increase this range, but Ruinous Extension (+8 meters) does increase the 'latch' range to 18 meters.
Would be great if DE could drop a note if this is intended or a bug. Since it impacts how people build around the grips. If there is no Range change all Secondary Vermispicers may as well just be Haymakers. If they are supposed to change range they may end up all being Gibbers (due to the low damage & high crit 'beam', and very minor loss in dama