The problem with having transporter relays in the solar system, or any inner planets of a star system, is that the planets are constantly moving relative to one another, not to mention the transporter relays themselves. If you had a whole lot of them at one orbital radius, then they would switch out and you could use them. Still probably easier just to use a shuttle, and much much cheaper.
The issue would be the distance between them rather than their locations so I suppose you would either end up building in a fair amount of redundancy and have some stationary and some following the orbit of the nearest planetary body. If you are aiming for a moon orbiting a planet, your transporter window would be even more specific since planetary bodies block sensors.
The Stargate bridge works because Stargate range is huge compared to a transporter, even a NuTrek transporter.