Originally Posted by
TravellinHusker
Yes, you will be considered an F pax and you can enter the Royal First Lounge. Just present your F boarding stub and your onward connecting stub.
The question was not just about the lounge, but also about the spa. I don't think they'll get access to any of these as they are on an int-dom connection.
It's worth a try getting through transfer security, but I have my doubts you'll be able to.