2 signals one pump

You need an electrician to answer your question. I have a circ controlled from two control points, but it is wired in parallel from the same electrical supply circuit. One control point is an aquastat and the other is an "always on" switch, which just as easily could be any other "on-off" switch. The key is that it is the same electrical circuit. I'm not aware that this is any problem, but again, check with an electrician to make sure your setup is safe and is OK for the equipment you are controlling.

You should isolate the control signals from each other (example) by using two fan coil relays to control the one pump

I did this with a pair of SPDT 10A relays. A little cheaper than separate fan coil relays. I picked up the relays at an electronics store along with mounting sockets and mounted then in a 4" square box. If i can find the schematic for how i wired them up i'll post it.

If it is on the same circuit, 2 " switches" in different places will not matter. When both are on, nobody knows the difference. If it is on different circuits ( a bad idea imo) then it would have to be on the same phase in you panel.- again when both are on nobody knows the difference. This becomes a servicing problem however to provide safe disconnect for the next guy.

I have heard of shared wells- between 2 homes fed from both directions, with a pressure tank in each home. Whoevers pressure switch is calling - their meter feeds it, again getting the phases correct is key, and providing proper means of safe disconnect for servicing. If you are unfamiliar- hire sparky

Jebatty answered this correctly, as long as it is suplied by only one circuit it is fine. I asked the same question of an electrical engineer a couple years ago, and that was his only concern.

you can use a pair of 845 or ra89 honeywell switching relays just hook the pump to out terminals of both relays jumped together and they have internal transformers so you hook your control wires from an aquastat or t-stat for example to t&t;Post exactly what you want to do and how you want to control it (dry contacts or powered) and I'm sure we can hook you up with a diagram