They are both at the same park. You'll just need to look at the calendar online at Disney and make sure Spectro is running, as it not an every night thing.
That's what I always do, watch Spectromagic... (my favorite parade, the music just gets to you.. I get all chocked up) and then just make my way to the Castle and watch Wishes... it's a wonderful way to finish the day!!!
Have fun!
DH and I normally just find our spot for Wishes in front of the Castle and watch Spectro Magic from there b/c there's normally only a 15min. interval between Spectro and Wishes and its a lot harder to find a good seat for Wishes than it is for Spectro Magic IOHO.
wow - I feel just the opposite. people stake out spots for spectro so far ahead of time along main street, that we like to watch it from frontier land; it's easier to walk up and get a spot along the rope, or even just behind someone. then when it's over, we hightail it through adventureland to main street. wishes is meant to watch from the FRONT of the castle. the show is not that long, so you don't need a "seat" just a piece of ground to stand on. then you are nearer the exit when it's over. (don't stand TOO close to the exit - they do not turn out the lights on the first few buildings) have fun!