Hi dana22,
Most Landmarks have 4 coax connectors in the Universal Docking Center (UDC) where all the plumbing connections come into the coach. Unfortunately, I'm not sure if this arrangement goes back to 2006 models. But let me assume it does.
Two of the connectors go to the rooftop pre-wiring for satellite dish. The other two go to the living room and bedroom. If you have a rooftop dish, you use a short jumper to connect the two connectors on the right, and another jumper for the left pair. If no rooftop dish, you don't use jumpers. The connectors to the living room and bedroom are usually the left side of each pair. (But it's pretty easy to get wires connected wrong behind the UDC, so don't get too heavily invested in which is which.)
The next part deals with the type of dish you have. If it's a round dish, it probably has only one coax connection coming off the LNB. The round dish provides a standard definition Directv signal to one receiver. I'm not sure if you can find a splitter to make it work for two receivers.
If you have an oval dish, it'll be either a Slimline 3 or Slimline 5. If the dish has 4 coax connectors, it's the older multiswitch technology. If only one connector, it's the newer Single Wire Module (SWM) technology.
With the multiswitch technology, you'd run a 2nd coax line from the dish into the UDC and connect to the connector believed to go to the bedroom. If you're not getting a signal at the bedroom receiver (connected to the satellite coax connector in the bedroom), try the other UDC satellite connectors. If none work, you may have a loose or shorted connector. Before running that down, try a direct coax line from the dish to the receiver to make sure everything except the coach wiring is working. If so, you'll have to go behind the UDC and behind the bedroom connector to inspect the coax connections. See if the connector is loose, or has stray wires shorting to the center conductor.
With SWM technology, you only need 1 wire from the dish. BUT, you need a SWM splitter (probably located in the UDC. Short jumpers from the splitter go to the UDC connectors for living room and bedroom. You'll also need a SWM power inserter (probably located in the living room) inline with the coax going to the living room receiver. If you've got all this and the living room works, run a piece of coax directly from the splitter to the bedroom receiver to make sure the basic setup is working. Then investigate the other connections and check the connectors.
If you have only one receiver, and are trying to use an output from that receiver to send signal to both living room and bedroom TVs, that's an entirely different problem. Some people have had success running a coax output from the living room receiver into the living room TV antenna connector to send the TV signal backwards through the antenna/cable wiring. If this is what you're trying, make sure the signal booster is turned off so it doesn't interfere with the signal. It's also possible that the splitters and signal booster are only passing signal in one direction. Dealing with that problem gets more complicated, and a wireless solution may be best.
And of course, the receivers have to be compatible with the type of dish you have. Some SWM capable receivers will also work with a multiswitch dish (but need to be configured correctly) while others will not. No older multiswitch receivers will work with SWM dishes.
Hope something here helps.