There’s some branding (Absolut Vodka) visible in the Luxury poster. thats the first thing I saw when wondering why they might reject you design. They would almost certainly flag that up with you…
Last year I uploaded a photo to photodune with the smallest half-logo ever and they noticed it and flagged it up with me. Simply got rid of that and resubmitted (they accepted).
As for the second poster, they may have rejected it due to the “8th March Party” part not being editable.
On a side note… “Free Drinks” and “Free Parking”?? That nightclub shouldn’t be encouraging drink driving. haha. 