Used them just last month for a package.
Yes, you get tier miles.
Interestingly, looked at same flights on Emirates website before booking holiday - only flex fares available for dates i wanted. Booked whole holiday with Emirates Holidays and flights came through as Savers......
Told rep i wanted to pay for flights in full there and then as the 'deposit' so i could get the actual tickets issued by the airline, not just a 'virtual' PNR that would not allow me to select seats. (And understand what the seats element of the holiday actually cost me....)
Flights were considerably cheaper than the website quote i got, so looks like they get genuinely cheaper seat allocations from the parent company.
Hotel choice is rather thin though.