Yes, make sure you recommend your Dad and brother and you will get 10,000 miles (for each of them) when they take their first flight.
Whilst you can't transfer miles, you can use other members' miles. For example, our daughters each have around 30,000 miles (which they got from flights we paid for) and we've just used some of them for our flights in January. I'm booked on the revenue flight and we used their miles to book a Companion flight for dh. It's also worth noting that you can book each leg of a return flight separately. We needed 30,000 miles for dh's Companion PE flight, but neither of them had quite enough, so we used 15,000 from each of their accounts to get the return trip.