You don't need to use a three-phase transformer if you only need a single-phase 110 V supply. If you're going to put in eleven 110 V points you may want to use three-phase just so that the loads on each phase are reasonably balanced.
simulate this circuit – Schematic created using CircuitLab
Figure 1. Star (wye) connection and delta connection. (Voltages are standard European voltages.
You can use transformers with 240 V or 415 V primaries depending on whether you are connecting in star (wye) or delta. Figure 1 shows only one phase. You need to figure out whether the 110 V secondaries are to be isolating or have one conductor neutralised or centre-tapped for 55-0-55 configuration depending on your application and local regulations.