The only VS miles you will earn will be from the spend on your VS credit cards. You obviously won't get any miles from the flights the people you are buying for actually take.
Personally I don't use shops away preferring to get cash back but IIRC then Expedia (other travel agencies are available) is on shops away and there are sometimes bonus offers on there - double miles etc which would be in addition to your spend miles.
I see the Virgin Money ISA has been suggested BUT an ISA isn't for everyone especially as there are requirements on how much money you need to deposit and poential withdrawal penalties as well.