The result means the reigning champions will finish the round in second spot after Sydney FC and Melbourne Victory drew 1-1 later in the evening.
Ibini’s fifth goal of the season came after the Mariners had let the Wanderers back into the match when Nikolai Topor-Stanley levelled proceedings five minutes before the break after Joshua Rose had given the Mariners the lead in the 32nd minute.
With two weeks to go in the home and away season Moss says competition for spots is hotter than ever.
"I have said this to the boys for the last three to four weeks, ‘no-one deserves to be on the bench and no-one deserves to be in the grandstand,'" Moss said.
"Every single player who is a Mariners player at the moment could be in the starting eleven so it’s a very, very tough job every week picking the team and picking the bench. So the boys that come on and do their job doesn’t surprise me at all, we know what they are capable of, Bernie (Ibini) and Dukey (Mitchell Duke).
"Monty (Nick Montgomery) came on and steadied the ship in midfield as well."
"When everyone is pulling their weight and doing their job this is the end result, you start to get three points every week."
Moss went on to talk up his side's title credentials, saying the Mariners performance demonstrated what they can do against the league's top teams.
"Tonight we just made a statement that we are here and we are here for keeps.
“We can achieve whatever it is we want to achieve if we can perform like that on the big stage against a quality side like Western Sydney and I thought there was a few questions thrown up this week about what class we had and I thought we answered those tonight."
Meanwhile, Western Sydney Wanderers' coach Tony Popovic felt his side were unlucky to walk away without a point after putting on a "totally dominant" display in the first half.
“It’s a tough one to analyse because in the first half we were outstanding, an excellent performance in the first half away from home.
“(We) totally controlled the game, dominated the game, it would have been a disaster if we had gone down 1-0 down and then the second half we weren’t good enough, simple as that we weren’t good enough.
“All the things that we did well in the first half we didn’t do well in the second and we kept inviting pressure and inviting pressure and they got that goal right at the end.”