Bias Tee design for 150V AC and 150 DC at 40 - 50kHz
Yes. The one time I needed a bias tee circuit is when I built PA0RDT's capacitative antenna. There is a full supply schematic on pages 14-15 here that should give a sense of how it is made: http://dl1dbc.net/SAQ/Mwhip/Article_pa0rdt-Mini-Whip_English.pdf
In the wiki page you linked there is a statement just above the formulas you quote: "Typically, the characteristic impedance Z0 will be 50 ohms or 75 ohms".
I don't really know what "wrong doing" you imply, but I'd definitely go for a fuse in the bias supply to protect the line and the power supply from short circuit surges. I used resettable fuses for convenience.