I want to fly with AA and LAN on this route

CLT-MIA
connect
MIA-LIM

[on all AA metal]

return

LIM-PJU (Punta Cana) STOPOVER [flight 2595 to miami stops here and this is thus a n.american gateway as defined by Aadvantage]
continue on LA2595 2 days later

PJU-MIA
connect
MIA-CLT (AA)

Is this a 'legal' routing

and is it worth using extra miles to fly business on LAN or AA?

best

Rich