Can people be saved without being baptised into the holy spirit?
No, they can not. Our seal is the holy spirit.
Apollos taught the baptism of John, then Paul came and said have you received the holy spirit yet?
They had not received the holy spirit, because they were not saved yet.
14 When the apostles in Jerusalem heard that Samaria had accepted the word of God, they sent Peter and John to them. 15 When they arrived, they prayed for them that they might receive the Holy Spirit, 16 because the Holy Spirit had not yet come upon any of them; they had simply been baptized into the name of the Lord Jesus. 17 Then Peter and John placed their hands on them, and they received the Holy Spirit.
The above people were saved but had not been baptized in the Spirit. How do we know that they were saved? When Peter and John got there they prayed and laid hands on them. Nothing is said about them baptizing them which they would have done if they were not saved. How do I know that Peter would have baptized them?
44 While Peter was still speaking these words, the Holy Spirit came on all who heard the message. 45 The circumcised believers who had come with Peter were astonished that the gift of the Holy Spirit had been poured out even on the Gentiles. 46 For they heard them speaking in tongues and praising God.
Then Peter said, 47 "Can anyone keep these people from being baptized with water? They have received the Holy Spirit just as we have."
The above were baptized with the Spirit which was a clear sign to Peter that they were saved. The first thing Peter said was lets baptize them in water.
I guess that one could try to discuss if Phillip knew the proper way to baptize. Then we would have to discuss if God really does equip those that He sends out.
The Apostles received the Spirit of Jesus prior to their baptism of the Spirit on Pentecost.
19 On the evening of that first day of the week, when the disciples were together, with the doors locked for fear of the Jews, Jesus came and stood among them and said, "Peace be with you!" 20 After he said this, he showed them his hands and side. The disciples were overjoyed when they saw the Lord.
21 Again Jesus said, "Peace be with you! As the Father has sent me, I am sending you." 22 And with that he breathed on them and said, "Receive the Holy Spirit. 23 If you forgive anyone his sins, they are forgiven; if you do not forgive them, they are not forgiven."
The above happened on Jesus' resurrection day. It seems as though baptism of the Spirit does not always occur at salvation.