I am not a regular user of Tamiya primer, but priming metal like PE is more of a challenge than priming plastic. I always use a primer intended to prime metal when priming PE, and also make sure it is absolutely clean before priming.
As to priming plastic, there are two main reasons to prime- first to improve adhesion, second to cover minor imperfections, seams, sanding scratches, etc. The second requires a fuller bodied primer. I use Krylon, which is very full of solids- it covers imperfections very well, but can obscure fine detail, so I can see a "fine surface primer" would be good for just improving adhesion without obscuring detail, where I have no imperfections to fill.