While I would never think of recommending a stock, savings bond rates are based upon a LAGGED average of interest rates; therefore, there actually is some value in timing your purchases. Be that as it may, there doesn't appear right now, IMHO, to be a clear cut answer to the question of whether you should wait or buy now.

I am actually more concerned about your first statement. Since you are planning on buying a house within one year from now, I hope that you are aware that you cannot redeem your bonds for the first six months. (Really 5+ months -- see other discussions on savings bonds for lots of discussion about timing of purchases). Given that, a purchase late this year or early next year may not be available to you for a housing purchase made next year (or, at the least, won't be available for your deposit). In that case, depending upon the timing of your home purchase, you may want to buy now.