This problem may be something TIME itself will eventually help fix. When I watched Tannehill throwing deep, two thing stood out......
1. Both Tannehill and Wallace still are not in sync:
How many time did Tannehill throw further then Wallace was because Wallace slowed down, or Tannehill did not throw far enough to lead Wallace deep in hope of not overthrow him, while Wallace was going full boat. Because Tannehill had little time to figure out the coverage, or how fast and how far Wallace would be from the defender, he was guessing, while still trying to not to throw an easy INT.
2. Time to set himself and throw more accurately:
Not knowing each other well enough yet still was not a big deal, because if Tannehill had been given just a bit more time to throw, he would have thrown better and more catchable passes. I noticed almost every time Tannehill went deep, but had average to good amount of time to see the coverage, set himself, and throw the ball, the pass was exactly or very close to where it needed to be for Wallace.
Fix the O-line, allow these two more reps with each other, and I am positive this will be a lethal combination in the making. I also hope Lazor will allow Tannehil to move in the pocket when he feels the pressure, when Tannehill passes on the run, it's almost unfair how dangerously accurate he is.