If screwing track to a concrete floor it is best to use anchors for the screws or you could use Tapcon screws.
There are different types of t-mouldings. Here is a link to the installation instructions for the Zamma universal flooring components. Zamma components use a base channel.
If you are installing a solid wood transition, Like the Home Legend you can screw, nail or glue it down.
Apply beads of flooring adhesive along the tongue of the hardwood/bamboo
flooring and on the subfloor in front of it. If further assistance is
needed please contact our Techincal Support Department at 877-630-1800.
If you used concrete screws (e.g., Tapcons) did you use the Phillips headed ones like Charlotte pictured above? If so, the metal channel isn't thick enough to allow the head to fully seat and you will get wobbling. You could replace then with the hex headed version but I'm wondering if there's enough room left for the "leg" of the T to fully seat. Since you already have screws and holes, I'd just pull the screws and use a bead of construction adhesive below the metal channel. Re-drive the screws to hold thing is place until the adhesive sets up.
In the future I'd just use plastic anchors and screws, sometimes provided with the moulding. The moulding experiences no stress and they are more than sufficient to hold it in place.