The gift of tongues, according to I Cor is called "various kinds of tongues." When Paul says "not everyone speaks in tongues" he is talking about the gift "various kinds of tongues" in context of that chapter. When people are baptized in the Holy Spirit; Acts, is sometimes silent as to what occurred. It is something that was evident and at least two times Acts records that they spoke in tongues, one time they prophesied, one time Simon saw something. The evidence given though incomplete, points to the baptism of the Holy Spirit is given to all and that speaking in tongues (not the gift) is generally the outcome.
Where it is confusing is this baptism of speaking on tongues, is not part of the gift "various kinds of tongues." I think that speaking in a foreign language for instance is part of the "various kinds of tongues." It cannot be proven either way. The reason for that is because one can speak in tongues, or pray in the spirit at will. Whereas the gift various kinds of tongues is "only as the Holy Spirit wills." Most do not recognize that difference. I note too that there is a set apart ministry of "diversity of tongues." I Cor 12:27-28. Sadly, the church does not really recognize this position or even realize the impact. To answer the question, I believe everyone baptized in the spirit, can speak in tongues. However, it generally is not part of the gift, various kinds of tongues.
That is about as careful as I have gotten on this. Over the years, I have made some good progress. It is not too uncommon in Pentecostal beliefs. Most however assume that the foreign language speaking in Acts 2 is merely the baptism. I disagree, again, because one cannot speak in a unknown foreign language at will like that. The same is for those that received the baptism of the Holy Spirit and prophesied. They were baptized in the spirit and went straight to an operation of a gift of the spirit. Had there been follow up on their baptism of the spirit, it would likely have shown that they could also speak in tongues at will too.
The idea of speaking in tongues at will, without interpretation comes from various other scriptures. Such as:
Jude 1:20 (KJV)
20 But ye, beloved, building up yourselves on your most holy faith, praying in the Holy Ghost,
Of course that could be English, but Paul prayed in tongues more than all and it seems doubful he was interpreting all of that.
Rom 8:26 and the verses in context I believe are about the believer praying with the Holy spirit with groanings too deep to utter. It is this praying in of the will of God that opens the door for the Romans 8:28 to occur. It is somewhat complicated in getting there, but it is just one possible interpretation. I am fine with those who disagree. I cannot say this teaching orginates from me but I have studied under some good Pentecostal teachers and in totality this type of doctrine fits the entire word of God on the subject better than anything else I have heard. I can expound more if you like or answer any question more fully. As to various interpretations, the bible is full of controversial doctrines concerning eternal security, what happens when you die (sleeping dead), tithing for the NT, end times rapture and tribulation, etc. So judgment calls have to be made with the teacher of the Holy Spirit in so many areas. Anyway, thanks for listening and pointing out potential deficiences.