The dictionary for Illustrator says that compression can be applied via the Illustrator save options:
Illustrator save options‚n : Options which may be supplied when saving a document as an Illustrator file
properties
compatibility (Illustrator 10/Illustrator 11/Illustrator 3/Illustrator 8/Illustrator 9/Japanese 3) : what Illustrator file format version to create ( default: Illustrator 11 )
compressed (boolean) : should the saved file be compressed (default: true, version 10 or later) ( default: true )
embed ICC profile (boolean) : embed the document’s ICC profile in the saved file (version 9 or later) ( default: false )
embed linked files (boolean) : are linked image files to be included in the saved document (versions 7 or later) ( default: false )
flatten output (preserve appearance/preserve paths) : how should transparency be flattened for older file format versions (pre-version 9) ( default: preserve appearance )
font subset threshold (real) : include a subset of fonts when less than this percentage of characters are used (version 9 or later) ( 0.0 - 100.0; default: 100.0 )
PDF compatible (boolean) : save as a PDF compatible file (version 10 or later) ( default: true )
However, I have tried including (compressed:true) in my code and also not including it”since it claims it does this by default. Either way it does not appear to apply it.
Is this a bug in Illustrator or am I overlooking something with how I set up my save options?
save current document in newFile as Illustrator with options {class:Illustrator save options, embed linked files:true, PDF compatible:true, font subset threshold:0.0, compressed:true}