Just to add a bit of information to the fray...
On Jetstar A320s we have 177 seats; 30 rows on aircraft-left (ABC) and 29 rows on aircraft-right (DEF).
We have a half-galley down in the aft so the lav sits in the half where a full-size galley would normally be, therefore we can have an extra row on the left. But there is no window there for the Alpha passenger and row 30 is usually one of the last to be filled because we try and block it for crew-rest.
However, on some of our aircraft that are leased or have come in from JQ Asia and other carriers (-JQW is one of them, the "Turkish Delight" one), they have only 174 seats because there is a full aft galley and therefore a lav sits on the LHS too, meaning 29 rows on both sides.
I haven't seen the inside of a Tiger A320 so if they have the same full aft galley with 2 lavs and yet they still seat 180 then I would imagine their seat pitch would have to be less.
As for the pitch being less on the RHS forward of the overwing because of that fwd bulkhead, I've never noticed that. As far as I can visually remember row 1 DEF starts at the same point as ABC - but I'll have a squiz at that next time!
