Don't assume his choices are suboptimal. How a person uses the tools he has matters far more than the specific tools themselves.
For example, my first 3e character was a gnome rogue/illusionist whose first feat was Skill Focus: Craft (Gemcutting). Suboptimal? In combat, sure. There were plenty times I wish I'd taken Point Blank Shot instead. However, outside of combat, my PC became an awesome financier. He'd regularly figure out how to get the best price out of the treasure horde, could make any gems and jewelry worth more without much risk, and created fake magical artifacts regularly and to great effect from an RP standpoint. The rest of the party loved the way he could squeeze every last copper out of any transaction and any loot. (Another "suboptimal" choice, Nystul's Magic Aura, was vital to making this work.)
Then, he got Craft Wondrous Item. Suddenly, he was making half of everything he ever needed for pretty much anything. He started turning loot into power-ups. He might not have ruled combat, but he ruled downtime.
The point is, don't assume that a nonstandard choice is suboptimal. He may have very valid reasons for his feat choices, and you might not yet understand or appreciate the value. After all, since Handle Animal, Ride, Jump, and Tumble are all cross-class for wizards, Animal Affinity and Acrobatic are the equivalent of 8 skill points each!
That said, if you're concerned about his feat choices, it's okay to want to learn more. If he's got a good strategy that you haven't seen, it would be good to figure it out.
On the other hand, if he's new to the game, he might not understand how the feats work. Animal Affinity? Awesome! I can raise dragon pets now! Acrobatic? Keen! Watch me get all Matrix-y! Alternately, he might think that the bonuses he receives add to his ranks for the purposes of synergy. If his feat choices aren't giving him what he's looking for, then definitely, it's okay to point that out to him. If, for example, he wants a dragon pet, then help him figure out a way to get one. If he sees himself as an awesome tumbling spellcaster, help him figure out how to make that. However, the fact is, neither one of these design choices are bad. Unexpected, perhaps, but not foolish.
By the way, what is an "optimal feat choice" for a wizard, anyway? Metamagic sucks rocks at low levels. Many magic item creation feats are out of reach. The ever-so-commonly-suggested Toughness is, in my opinion, a waste.
In the end, don't assume his choices are suboptimal. (Yes, I said that three times. It's that important.) Figure out what he wants to make, and help him make that. Then, figure out how his unique skill set helps you and the party. I guarantee you, there is a way. Finally, remember that how you use the tools you have is far more important that exactly which tools you have. If you can't use a friendly wizard who's good with horses and tumbling... that's your problem, not his.
Myself, I'd figure out how to get this guy a group of trained monkeys, so that he could vault himself into a hidden location and send out a troop of magically-enhanced creatures that could steal stuff and confuse the enemy.
Figure out what he wants. Make that rock.