I think it's best not to think in terms of matching, because that can get boring. Think in terms of harmonizing. I think the only thing that really matters is -- do you like the way those fabrics look together.
I like the fact that your two prints vary in scale (that is, the butterflies are large and the squares are small); I've found that's very important for a pleasing look. Also, the butterflies are free form and curvy while the squares are regular. Contrast like that is nice. While I agree with Bree that the green and pink in the little squares print are quite different from the greens and pink in the other fabrics, I kind of like them together.
I would suggest you experiment a bit -- just throw some other fabrics on top of those and you might find some combinations you like even better. But I think these would make a nice pillow.