Allan, Ciarán, all,
I used the phpdoc snippets a lot in TextMate. I also go back and add to those phpdoc blocks. When I go back and edit those blocks TextMate doesn't provide any help.
I created a command and snippet to help: The Command provides Auto complete when you use a @ in a phpdoc comment. The second file is a snippet for when you hit enter it puts an asterisk at the start of the next line.