A travel package can always be a good idea. (points to cover hotel stay and points transferred into your airlines mileage program) I like to use the "flight miles" to upgrade from Coach to either Business or First Class, especially for long-haul flights. ( I purchase with cash a coach ticket and use flight miles to upgrade.)
However with summer just around the corner, the reasonable "bump up" options may be all taken. Then the airlines have you by the b***s and of course they will charge you a "premium" amount of flight miles to upgrade. Is it worth it? Probably not-if you like to sit in coach for flights longer than 4 hours.
Have a fun time in Spain. It's on my bucket list.