If a match is interrupted for any reason, and is replayed in full, this will be treated as an abandonment and bets on the original fixture will be void, except for those bets the outcome of which had already been determined, prior to the initial interruption in fixture.
Yes, it is possible to bet on both teams involved in a match at Bet365. This is known as "hedging" a bet. It allows you to place bets on both teams, effectively reducing your risk and potentially earning a profit regardless of the outcome of the match.