I doubt
either would be wanting her. Until her dad dies in 1548, she's in his custody. And her dad was a member of the Schmalkaldic League
against the Emperor. There's even some suspicion that Philipp wanted a match with Mary in order to gain English support for his designs on the imperial throne.
@RedKing I might be mistaken on this part. While Phil was a member of Schmalkaldic League, Cardinal Farnese (in a 1539 letter to Paul III) and the French ambassador to Henry VIII (Marillac),
both describe Philipp in their letters as "Catholic". So he might have been a religious opportunist.
The news is confirmed that he [Marillac] wrote on the 24th touching "the
marriage of Lady Mary with this duke of Bavaria; who three or four days ago, as secretly as he could, went to visit her in a house of the abbot of Westminster, in the gardens of the abbey, a mile from this town, whither she had been brought. After having
kissed her, which is an argument either of marriage or of near relationship, seeing that since the death of the late Marquis no lord of this kingdom has dared to go so far, the said Duke had a long conversation with her, partly in German through an interpreter, and partly in Latin, of which she is not ignorant. Finally, they mutually declared, the said lord his resolution, taken with this King, to have her for wife ...and the said lady [Mary Tudor]
her willingness to obey her father. Cannot tell when the marriage will be consummated; but some say in 15 or 20 days, others that the weddings of father and daughter shall be on the same day, that is, as soon as the lady who is at Calais [Anne of Cleves] arrives. ... London, 27 Dec."