Out of interest, if you are flying VA SYD/MEL- LAX, then onwards to IAD with VX, is there a change of terminal at LAX?

Also slightly OT, but I cant seem to get the points calculator to work out the SCs for that trip. It is 3 flights to the USA: SYD MEL, MEL LAX, LAX IAD and on return is only two flights IAD LAX, LAX SYD.

Can anyone help out a semi-newbie VA flyer with this please?

Most likely flying cheapest Y fare at this stage and its for my daughter (but I have family pooling) ^.

Thanks