Good to know for future reference. Yes, RCI is generous so to speak with the luggage tags. It can't hurt to pack the extras in the bags that you plan to carry on on the plane. The reason being, if you attach the tags to the bags before you leave home, and find that they're missing after you claim your bags, you can attach another tag.
However, if you're flying down the day before, then your best bet is to attach them at the hotel.
2007 - Majesty of the Seas
2009 - Enchantment of the Seas
2010 - Freedom of the Seas