Positionally yes, but technically no! For salvation was not even possible for anyone until Christ's death and resurrection, as peoples sins could not be removed by Christ's blood until after the resurrection. So the righteous dead who died in the OT were kept in a place called Abraham's Bossom until such time as whent he blood of Christ was applied and their souls then went immediately into God's presence in heaven.

The apostles were saved (positionally) before the cross, but as the blood of Christ had not yet been applied, they remained like every other OT saint in their sins and still awaiting salvation when the blood of Christ (i.e. his life) would then remove their sins. I guess that this happenned at the resurrection rather than pentecost, but I'm not certain.

Pentecost involved the giving of the Holy Spirit to the Church, this was a unique event which hasn't been repeated since. The apostles were both baptised and then filled with the Holy Spirit in this unique event.