In short, maybe. Birds build nests to safeguard eggs and nestlings from predation (and sometimes to keep them warm), so nests are often hidden, not easily accesible and camouflaged. So to the degree that a fake tree provides these qualities, then a bird may choose to build a nest there, depending on what other options are around.

I'll agree with lunafish. Birds can be very adaptable and will pick any convenient nesting spot if it offers enough protection, whether it's natural or clearly artificial. Here in New York, pigeons are quite happy colonizing elevated stations of our mass-transit rail, and we've got hawks nesting on skyscrapers near Central Park. When I lived in a different city, I've had swifts nest in the thin space between the roof of a covered balcony below and the floor of our balcony.