Is Macbeth totally honest with his wife throughout the whole play?

No, Macbeth is not always completely honest and open.  The
most obvious part comes in Act 3, sc. 2.  In this scene, Macbeth is purposely evasive
with Lady Macbeth when the two of them talk about Macbeth's nervousness.  Macbeth tells
his wife that he is worried when he says "O, full of scorpions is my mind, dear wife!"
(l.  41).  She goes on to tell him that Banquo and Fleance (who the witches have
predicted will beget kings) cannot live forever.  Macbeth has already talked to the
murderers so the audience knows that Macbeth plans to have both Banquo and Fleance
killed, but it is obvious from this conversation that Lady Macbeth does not know it. 
Macbeth even says, "Be innocent of the knowledge, dearest chuck, / Til thou applaud the
deed," (ll. 51-52).  Later, in Act 3, sc. 4,  when the ghost of Banquo appears at the
dinner, it is only the gulit-ridden Macbeth who sees the ghost, not Lady Macbeth. 
Macbeth may not have told his wife his plans because he wanted her to have plausible
deniability or because he was protecting her from more crime.  We aren't sure what his
motive was, but it is clear that he did not share this information with her before the
murder took place.