I like the style of illustration you used for the flowers, I feel it gives it an Art Nouveau style and makes it look high end, as the brief asks for and the use of colour reinforces this high end idea. On the other hand, the typography has very thin lines that are going to be difficult to print and it doesn't match the typography on the front with the one on the back because you used a typeface with a high visual weight I would use its medium version at the most. I also feel that on the back you have a lot of space and you crammed everything in one place. Lastly be careful with the margins, your text is too close to the edge and can be cut off during the printing process.