Well, Dog Wizard is more Antryg's story, not to mention it's set in the Citadel of wizards way up in the middle of nowhere--Joanna is in it, but not so much (although, when she does show up, she is fabulous, as always) until the last five or so chapters.

Stranger at the Wedding is set several months after DW, and isn't related, except that Kyra Peldyrin (spelling possibly incorrect, as my copy is in hiding, since I re-read it not that long ago) was one of the younger mages/wizards in DW. It's... It's about her sister, and her own past, and growing up as a wizard in not-so-certain times. Sort of. It's actually more serious in tone (well, except for the Suraklin bits are pretty damn creepy), but still has bits and pieces of humor.