If I'm understanding the situation correctly, you have two houses next to each other, one with a crappy well and the other with a good well which will provide enough water to both houses if you could connect the systems. If these houses really will be owned and sold together then the water systems could be connected by burying a section of ABS pipe and providing the correct valves etc. However, if there is even a chance the houses might be sold separately then I would avoid connecting these water systems as it will cause all sorts of headaches down the road for the different owners. Because of this I would suggest adding a storage system to the house with the crappy well so the cistern is slowly filling all the time but will allow for plenty of water when you need it. I installed systems like this in the past using a plastic tank which can be moved into the basement and which has a float valve to shut that water off when the system is full. The water in that system will be un-pressurized, so you woudl then need to add an additional pump and pressure tank to send water to your house. If you don't mind the noise this could be a centrifugal pump but we used a submersible pump with low pressure shutoff since it was silent, never needed to be primed and would not run dry. A benefit of this system woudl be you could also temporarily connect the good house to the storage system if that well ever ran completely dry and at least keep water in the house.
Sounds complicated but it really isn't. Good luck and feel free to drop me a line with any questions.