Is there a setting while saving as a .pdf

Question

so that'll it'll use the objects to determine the boundaries (like an eps) as opposed to the page size?

Answer 1

Aarmed,
For what it's worth, I don't get it either. You said nothing about wanting to import the PDF into InDesign. You just want to export a PDF with a page size that matches the artwork bounds.
The omission of such a setting in the Save As... PDF dialog is just like Illustrator's failure to provide a common-sense checkbox in its various export dialogs to simply export the selected content.
You can do this:
Rather than Save As...>PDF, select Print.
In the Print dialog, General pane, select Adobe PDF as the "printer." Set the Media size to Custom.
In the Setup pane's Crop Artwork To popup, select Artwork Bounding Box.
Click Print.
The resulting PDF will be cropped to artwork bounds.
If you have Acrobat installed, and it is your default PDF reader, and you have the View PDF After Saving option on in the Save PDF dialog, then the above digging is no less tedious than saving as PDF, letting Acrobat launch, going to Document>Crop Pages, and clicking the Remove White Margins checkbox.
Both methods are ridiculously tedious. Crop To Artwork and Seletion Only checkboxes should be present in all Illustrator's export dialogs. But then, it took Illustrator 20 years to finally acquire a Fit To Page checkbox in its Print dialog, too.
JET