I am pretty sure that you are looking for a setup of this kind:
(Simplified setup)
If I understand correctly, you've actually solved most of the task already, it's just that you haven't managed to rotate the petals for the individual flowers yet.
The trick here is, after instantiating the circles where you create the petals, to capture their index.
You do this with Capture Attribute in the domain Instance. This way you have a unique index per instance, and can use this value additionally to calculate the rotation of the petals.
In this example I simply used the node Random Value for this and used the previously captured index as ID.
I then add this randomly generated value here with the rotation of the petals along a circle.
With Vector Rotate and Align Euler to Vector I then create the corresponding Rotation for the individual instances.
(Blender 3.2)
Update
You can, of course, add more random angles by adding different angles to the rotation. Note that these values are in radians, not degrees.
Because of this setup, each individual point at which a petal is created has a unique index and does not represent instances, so too is the rotation created for each petal unique.
