Looking at the first below I'd say, to be on the safe side, the bedhead should show half to three quarters above your tallest pillow. The second photo I believe shows too much bedhead.

Thanks all for your advice. Ive included some renders that I made with view along the corridor with and without the bulkhead. I don't think renderst does it justice until you actual walk through @ frame stage. I agree that ceiling height and comfort and look, depends on climate, orientation, insulation, relative proportions of other parts such as windows/doors. Because of the Melbourne climate, we have planned for double glazing, and good insulation with R2.5 batts wall, R6.0 ceiling. We have 2.4m height of windows and door around the ground floor which is btw 3 to 3.6m so I think proportion wise should be ok. In the family where it was always planned 3.6m from the start, we have a band of clerestory windows too. We have decided not to be too excessive with windows ( ie 3m and even 3.6m floor to ceiling - how grand would have that looked though! ) to minimise heat loss during winter. Energy rating for house is 7 stars so far. Thanks for giving me the pro and cons - I have some more confidence to let it stay at 3.6m throughout now.

Renovating or restoring as many Victorian features as possible .....Should the 3300 section of your hallway have the original cornice, retain/restore, Many Victorian terraces have a bulkhead along the hall with arch and corbels.

What height window and doors are you proposing. If 3 metre ceilings then 2400 doors and windows would look better. This will then add extra cost for window treatments. Also in the kitchen, with a 3 metre ceiling, where would you stop your overhead cabinets, would you have them to the ceiling? Or standard height? I personally would do your pitched ceiling in living area, and 2700mm everywhere else. This will add extra interest with the change of ceiling height. 2700mm are a good height.