Interesting question.
All of Jervis Bay is part of the ACT. Although for the most part NSW Law applies, it remain a part of the Australian Capital Territory.
Yes, there are different regs depending on what part of the Bay you are on. Sounds like the ranger was pulling you along a bit. Where you launch you boat means nothing...it is where your boat is when you catch a fish that matters.
Within JB if no limits are stated for a particular area, then NSW limits apply.
Booderee does have squid limits of 10 per person. As such, NSW limits only apply outside of Booderee waters...Confused yet ??
Here is a link to some info - https://www.environment.gov.au/system/files/resources/48329a7b-cb98-4e0c-84f0-7fe788a1353c/files/marine-activities.pdf
Which includes this - "
(NOTE: Fishing bag limits are the same as the adjoining NSW
waters, with the exception of squid collected - 10 per person)"
itsaboat mate...Life is just a boat and then ya marry one !