In 2006 I did a real world project where I solved some parts in PROLOG. I thought about available Perl-only logic programming solutions on CPAN but after some experimenting recognized Language::Prolog::Yaswi as the best choice because sooner or later you need some real PROLOG-only features and you need to ask the according communities, which can better help you when referring to a real PROLOG they know.
The existence of this lib also was my primary decision criterion for SWI Prolog over GNU Prolog.
I used both directions, mostly PROLOG from Perl but also provided some functions from Perl to the PROLOG library (namely some DateTime functionality). It worked as documented, although as usual you should take some time for fiddling the best way how to organize both your Perl and (mostly) your PROLOG libs, e.g. when to use libs and namespaces, where to store PROLOG files, etc.
For testing I can recommend the "Autotest for SWI-Prolog" library which I simply adapted to print out TAP. This way you can test the PROLOG subsystem and the integration from within your Perl project.
The author was responsive for bugreports (something in SWI PROLOG had changed), investigated and fixed it. Everything felt matured (for those who don't trust version numbers below 1.00).
Thanks for this powerful lib that opens up a powerful different programming paradigm in The Right Way.