The only way to find out is to ask - and if you are on separate reservations then you need to ask about that specifically because (as already mentioned) some airlines will only interline tags if you're on the same reservation.

If it's important for you to know before the flight then phone or email them. (On a short-ish connection this could make all the difference). If it's not critical then just ask when you drop off your bag for the second flight (making sure you have your booking confirmation or boarding pass handy).