VS will issue you with boarding passes for both flights when you check-in at LHR as well as tag you checked bags all the way to MCO. Whilst your JFK>MCO flight will have a VS flight number, do make a note of the DL operating flight number which will be printed on your second boarding pass as that's the DL flight number that will be displayed on airport displays once you get to JFK.
When you land at JFK, even with your luggage checked to MCO, you still have to go through immigration and collect your luggage at JFK. Instead of exiting the terminal you than follow the signs for flight transfers and you simply drop your checked bag off at a generic bag drop area, go through security and then head to your next departure gate.
DL can be a bit messy at JFK as they depart from both T4 and T2 so do make sure you check your DL flight departure carefully. You will already be in T4 at JFK as that's the terminal VS are in.
There seems little logic to which DL flights use which terminal at JFK as I've done a couple of JFK>BOS flights on DL in the past and each one departed from different terminals at JFK!?!
For your JFK>MCO flights as you have booked Premium, you will be sat in Comfort+ which is the first couple of rows in Economy with a little bit more leg room. Everything else is the same as Economy though.
If you either go to the DL website or use their app, you can access the DL part of your booking and select seats in the Comfort+ cabin before check-in opens. It will find your booking by entering your VS booking reference number (and also give you another DL booking reference number).
The DL app is really good as it even allows you to check the progress of your checked luggage (even on the VS flight legs too when you booking contains a mix of VS & DL flights). I wish VS would add this option to their app!!
Regards
James Mitchell
