What was the mash temp?
What was the fermentation temp?
Hefeweizens are a difficult style to get right, especially when it comes to fermentation. I've found if the pitching rate and fermentation temp aren't right, it lacks the expected strong banana/clove. And with that kind of beer, the malt is subtle, especially if you just us a single infusion mash, and there's little hop to speak of, so as a result the end up bland.
I've found repeatedly that Hefes will benefit from a step mash (I do 45 mins at 110, 5 mins at 128, 60 mins at 152, and then 10 mins at 168), and I actually prefer them decocted, although most don't think it's worth the effort. However, for your initial all-grain batches that's likely biting off more than you can chew.
But with fermentation, I've found repeatedly that only by underpitching and fermenting cold (I fermented my Weizens at 60-62F) can I get the balance of banana and clove that I want. I've never used WB-06 (I like Wyeast 3068), but I'd assume it behaves like the other Hefe strains, fermenting too warm inhibits the clove phenolics, while overpitching inhibits the banana esters. End result is weak beer.
And with that gravity and a full pack of dry yeast, in this case you probably overpitched.