This distribution of TeXLive aims to save bandwidth and hard disk space by not including the full texmf tree. But what it does include is capable enough to satisfy most ports that list texlive as a dependency. In other words, you should be able to append to /etc/prt-get.aliases the line texlive-base: texlive and not run into problems. If you later find yourself needing TeXLive packages that were not included, there is sadly no tlmgr script to automate the installation from CTAN. You can download them from CTAN by hand, unpack them into /usr/share/texmf, and then run mktexlsr. Or create a port that does the same.