This is what I see (but it's a photo, and not sure if what I see is there)

didn't notice that when I bought it.

If it is a stone chip, then water can get under, and rusting can start. A professional shop can repair this, and it appears unlucky to maybe hidden for sale to me "which is the polishing n cutting, I think I see" and most second hand sales place may/will claim this standard thing they do to all vehicles, not just yours.

 

The bonnet is aluminium so that should be a warranty issues but good luck, is always a fight.

 

bonnet is aluminium

That being the case, it is not rust, but is a form of corrosion, there are a fair few versions, depending on what materials are present and damage. Something like oxidation with water and energy source (maybe assume wind/pressure), which forms white oxide on aluminium, and could form under the paint, once chipped - so a form of galvanic attack. Not really sure till the OP tell us what is present, just thinking out loud.

 

Thanks for the input - had no idea the bonnet is aluminium - makes it a pretty pricey item compared with sheet steel I would have thought. A magnet should settle this once and for all!

 

I saw the same issue on mine (same model) but spotted it before purchase so the dealer agreed to fix it which they did. Not sure it's the same place. Mine was on both front corners of the bonnet. Looked identical to yours. Must be some common defect.

 

I got a free repair with the dealer. Peugeot take the cost for several rust bubbles. Talked with p.dealer just before the five years warrant went out. Greetings from T Saetre, Oslo