No it doesn't. There is no contradiction between these verses. One is only speaking directly to the Jewish people. There is no contradiction between non-Jews being allowed to eat blood and Jews not being allowed to eat blood. The Mosaic Law is only for Jews. If it says Jews can't eat blood, that means nothing to non-Jews, who, as we can see from Gen 9:5, can eat blood (according to the Jewish interpretation).
No, God does not have two standards.
The scripture posted above in Acts was to the Christian congregation that included Jews and non-jews. And the Bible command was still applied to non-jews to abstain from blood:
(Acts 15:20) but to write them to abstain from things polluted by idols, from sexual immorality, from what is strangled, and from blood.
(Acts 15:29) to keep abstaining from things sacrificed to idols, from blood, from what is strangled, and from sexual immorality. If you carefully keep yourselves from these things, you will prosper. Good health to you!”
(Acts 21:25)
As for the believers from among the nations, we have sent them our decision in writing that
they should keep away from what is sacrificed to idols as well as
from blood, from what is strangled, and from sexual immorality.”
This was written by the older men in Jerusalem after a debate about the circumcision came up. Peter came from the field with an eye-witness account, he himself personally went through, how Jehovah direct him to the house of an uncircumcised gentile and baptized him with holy spirit.
When relating these things to the apostles and older men in Jerusalem they gathered together and with the help of the holy spirit they gave these commands to all Christians, both the Jews and non-Jews alike. To abstain from blood.