Velmont, you might consider retraining Bastion of Defense for Lead the Attack. Lead the Attack is considered to be the best of the Warlord attacks since it helps to prevent everyone from missng when it counts (daily and encounter powers) with your current stats it'd be a +3 to hit if you hit the target or a +1 if you don't.
IMO, Lead the attack is only much better against a solo monster. After all, it only grants the bonus againts a single target, though it's a whopping bonus. If you know for sure you will face a high percentage of solo monsters in your adventures, then it's the unequivocal best choice. But not all DM like to use a dragon or some other solo for each adventurer's working day.
As a matter of fact, I didn't use a single solo monster from level 1-4 in my first go at 4e (which might have influenced Velmont on that account). I've favored big, tough brawls for the final showdown, with usually at least 2x more baddies than PCs. I find them more exciting.
In those situation, bastion of defense crushes lead the attack. It's like 2 or 3time more useful, seriously. Lead the attack only helps you kill one guy (an elite in the best case scenario, sometime not even that) and then it's gone. And in a large melee, it's conceivable that you can't even arrange for all 6 PC to attack the same target if there is too much interference. Meanwhile Bastion works for the whole encounter. The addtional hps are a life savers when you get surrounded (In a group of 6you are talking 63 temp hps with 18 cha!) and the +1 to all defense is statistically bound to save you a few times when 10+ monsters are hammering you with 10+ attack rolls every round (especially if Area attacks a re involved). In fact, the larger the group, the more powerful Bastion becomes. And we're a pretty large group.
Bottom line; which is better is heavily dependant on the DM's style. But when in doubt, consider that Bastion is still pretty good even against a solo dragon but lead the attack is fairly weak in a 'heroes' last stand' scenario.