Of teleport, (PHB, page 281):
The spell teleports you instantly and up to eight volunteers creatures of your choice that you can see in range, or just one object that you can see in the range, to a destination you select. If you target an object, it must be able to fit entirely in a 10-foot cube and can not be held or carried by a creature that does not want to.
the teleport the spell can only affect creatures or objects (since it's a trap, I forget about it)ready creatures "in the description of the spell.) Therefore, since the" spectral floating hand "of mage's hand is neither a creature nor an object, RAW would not be teleported.
That said, you are the DM. This could be a unique teleport spell of your build (which also bypasses the problem of "willing creatures"), although the problem with this is that your players have no way to know what is wrong. this spell or understand how it works outside of your descriptions.
In the end, if you want to stick to RAW or ignore it, it's something you have to judge based on how your players would react if you deviate from RAW for such a trap.