Hi Joy,
I'm so glad you decided to keep this 2piece dress and also add it to your travel capsule. It truly is a classic.
Ok, now onto your new question. How to pair the 2 separates. Here are my thoughts:
1. The top is almost tunic length and hence very versatile. Wear it with black leggings or skinny pants --- it'll also work like a comfortable outfit for flights and for exploring the city. If you don't love black, you can pick any other neutral like beige, tan, navy, dark grey .... Whatever you love. The print on this dress is quite the star, so any solid neutral color works. Personally, I love black because it is also a great color for travel as it masks stains easily and allows for more wears when everyday laundry is out of question
2. I suggest the same colors for the top. You actually have a great shape for tucking. But if you don't want to tuck, any fluid blouse or shirt in solid neutrals that's ends at your hip bone will work. Tops with little details like gold/silver buttons and lace/sequins/embroidery detailing will keep the look fancy. Simple solid tees will dress down the skirt got a casual look.
I hope that helps.