Hi Piercarlo,
Thank you for your interest in Essential Studio.
We can retrieve the bounds of the grid by using the "PdfGridLayoutResult" class, it will be returned by the PdfGrid.Draw() method. Please refer the sample for more details.
Sample Link:
http://www.syncfusion.com/uploads/redirect.aspx?&team=support&file=95635-583735342.zipPlease try this and let us know if you have any queries.
Regards,
Angappan.