NOT TRUE!
I ever spoke to an Indian colleague who was invited to a Chinese
colleague's wedding dinner at a posh restaurant right in the heart
of Orchard Rd.
Her ang pow was...
S$20!!!
I was 
!!!!
So, you just can't assume that everyone will be generous, and you
will defray the costs with the ang pow's.
And, one more question, does this mean that those who have
financial constraints and won't be able to afford a big ang pow
that's 'enough' to cover the cost of the dinner per pax will not be
welcomed?
When the issue harpers so much on the monetary bit, that's when I
think that the entire spirit of the wedding dinner is lost.
Live within your means, celebrate within your means. I do not wish
to go into debt holding some fakey, lavish Chinese dinner, just so
I got 'mian4 zi3'! 
Even if I were to marry someone rich and had the money, I'd
probably do something like rent the entire Alkaff Mansion and the
gardens surrounding it, put up marquees (and make sure there's
those kewl mist-fans to keep things cool) and organise free
transport from designated pick-up points so even those without cars
need not fret. And then, hold a feast from noon till the wee hours
of the morn! 
